Two insulated wires, each 4.42 m long, are taped together to form a two-wire unit that is 4.42 m long. One wire carries a current of 7.33 A; the other carries a smaller current I in the opposite direction. The two-wire unit is placed at an angle of 69.4o relative to a magnetic field whose magnitude is 0.547 T. The magnitude of the net magnetic force experienced by the two-wire unit is 2.24 N. What is the current I

Answers

Answer 1

Answer:

Current I=6.34A

Explanation:

Given data

L=L₁=L₂=4.42 m

I₁=7.33A

Angle α=69.4°

B=0.547T

Force F=2.24N

Required

Current I

Solution

The length of each wire ,the magnetic field B,and the angle are same for both wires.

As we know that Force is:

[tex]F_{net}=I_{1}LBSin\alpha -I_{2}LBSin\alpha\\F_{net}=(I_{1}-I_{2})LBSin\alpha\\I_{2}=I_{1}-\frac{F_{net}}{LBSin\alpha}\\I_{2}=7.33A-\frac{2.24N}{(4.42m)(0.547T)Sin(69.4)} \\I_{2}=6.34A[/tex]    

Current I=6.34A


Related Questions

A projectile is fired with an initial speed of 230 m/s and an angle of elevation 60°. The projectile is fired from a position 100 m above the ground. (Recall g = 9.8 m/s². Round your answers to the nearest whole number.)
(a) Find the range of the projectile.
(b) Find the maximum height reached.
(c) Find the speed at impact.

Answers

Answer:

Explanation:....

The range of the projectile is 4675 m. The maximum height reached by the projectile is 2124 m. The speed of the projectile at impact is 234 m/s.

(a) Range is defined as the maximum horizontal distance covered by a projectile during its motion. It is given by the formula:

[tex]R = \frac{u^2 sin2\theta}{g}[/tex],

where u = initial speed of the projectile = 230 m/s

θ = angle of projection = 60°

g = acceleration due to gravity = 9.8 m/s²

Using these in formulas, we get:

[tex]R = \frac{(230 \hspace{0.8mm} m/s)^2 \hspace{0.8mm} sin2(60)}{9.8 \hspace{0.8mm} m/s^2}[/tex]

or, R = 4674.77 m ≈ 4675 m

(b) The maximum height reached by the projectile is given by the formula:

[tex]H = \frac{u^2 \hspace{0.8mm} sin^2\theta}{2g}[/tex]

using the numeric values, we get:

[tex]H = \frac{(230 \hspace{0.8mm}m/s)^2 sin^2(60)}{2 \times (9.8 \hspace{0.8mm} m/s^2)}[/tex]

or, H = 2024.23 m

However, since the projectile was fired 100 m above the ground, hence, the maximum height would be:

h = 100 m + H = 100 m + 2024.23 m = 2124.23 m ≈ 2124 m

(c) The speed of the projectile comprises of two parts, a horizontal velocity and a vertical velocity.

The horizontal velocity is given as [tex]v_x[/tex]. It is constant throught the motion and its magnitude can be determined by the formula:

[tex]v_x = v cos\theta = 230 \hspace{0.8 mm} m/s \times cos(60)[/tex]

or, [tex]v_x = 115 \hspace{0.8mm} m/s[/tex]

The vertical velocity is given as [tex]v_y[/tex]. It is not constant throught the motion. At the highest point, the magnitude of vertical velocity is zero. Using the kinetic equation,

[tex]v_y^2[/tex] = u² + 2gs, where s = h = 2124 m, we get:

[tex]v_y^2[/tex] = 0 + (2 × 9.8 m/s² × 2124 m)

or, [tex]v_y^2[/tex] = 41630.4 m²/s²

or, [tex]v_y[/tex] = 204.03 m/s ≈ 204 m/s

Now, the magnitude of speed will be equal to the resultant of both the horzontal and vertical velocities.

[tex]v = \sqrt{v_x^2 + v_y^2}[/tex]

or, [tex]v = \sqrt{204^2 + 115^2} \hspace{0.8 mm} m/s[/tex]

or, v = 234.21 m/s ≈ 234 m/s

By clicking the two-slit barrier and dragging it, you can change its position. Always allow a few seconds for the simulation to catch up with the changes you are making before analyzing the results. When the two-slit barrier is brought closer to the screen (and farther away from the source), what happens to the distance between two adjacent bright (or dark) fringes?

A. It becomes larger.

B. It becomes smaller.

C. It stays the same.

Answers

Answer:

the answer the correct one is B

Explanation:

The interference phenomenon is described by

           d sin θ = m λ

The spectrum is recorded on a screen, so we can use trigonometry

          tan θ = y / L

   

In this experiment the angles are very small, so

           tan θ = sin θ /cos θ = sin θ

  We replace

         d y / L = m La m

        y = m Lam L / d

When the slits approach the screen the value of L decreases,

Therefore the value of the separation between the slits must also decrease

When reviewing the answer the correct one is B

You are operating an 80kg reciprocating machine. The manufacturer notified you thatthere is an imbalance mass of 3kg on the rotating shaft, which has a 10cm diameter.The system was designed to have negligible damping.P.1.1What is the steady state amplitude of the machine’s displacement if you are operatingat very high frequencies?

Answers

Answer:

Explanation:

The system can be modeled as,

Using magnitude relationship for imbalance system.

Check attachment for solution

The six metals have the work functions, W.

Part A Rank these metals on the basis of their cutoff frequency. Rank from largest to smallest. To rank items as equivalent, overlap them.

Part B Rank these metals on the basis of the maximum wavelength of light needed to free electrons from their surface. Rank from largest to smallest. To rank items as equivalent, overlap them.

Part C Each metal is illuminated with 400 nm (3.10 eV) light. Rank the metals on the basis of the maximum kinetic energy of the emitted electrons. (If no electrons are emitted from a metal, the maximum kinetic energy is zero, so rank that metal as smallest.) Rank from largest to smallest. To rank items as equivalent, overlap them.

Cesium= w= 2.1 eV Aliminium= w= 4.1 eV Beryllium= 5.0 eV Potassium= 2.3 eV Platinium= w= 6.4 eV Magnisium=w= 3.7 eV

Answers

Answer:

Explanation:

W (Ce) = 2.1 eV

W (Al) = 4.1 eV

W (Be) = 5 eV

W (K) = 2.3 eV

W (Pt) = 6.4 eV

W (Mg) = 3.7 eV

Part A:

Work function is directly proportional to the cut off frequency.

let f denotes the cut off frequency.

So, f (Be) > f (Be) > f (Al) > f (Mg) > f (K) > f (Ce)

Part B:

Maximum wavelength for the emission is inversely proportional to the cut off frequency

So, λ (Ce) > λ (K) > λ (Mg) > λ (Al) > λ (Be) > λ (Pt)

Part C:

E = 3.10 eV

Let K is the maximum kinetic energy

K = E - W

K (Ce) = 3.1 - 2.1 = 1 eV

K (Al) 3.1 - 4.1 = not possible

K (Be) = 3.1 - 5 = not possible

K (K)  = 3.1 - 2.3 = 0.8 eV

K (Pt) = .1 - 6.4 = not possible

K (Mg) = 3.1 - 3.7 = not possible

So, K (Ce) > K (K) > K (Al) = K (Be) = K (Pt) = K (Mg)

Final answer:

Metals can be ranked based on their work functions, which determine cutoff frequency, the maximum wavelength of light needed to free electrons, and maximum kinetic energy of emitted electrons under specific light. Lower work functions result in higher cutoff frequencies and longer required wavelengths, and more energetic emitted electrons when under 400 nm light.

Explanation:

The ranking of the metals, in terms of cutoff frequency, maximum wavelength of light, and maximum kinetic energy, is based on the work function of each metal, which is the minimum energy required to free an electron from the metal's surface. The cutoff frequency is inversely related to the work function, so the metal with the lowest work function (cesium, 2.1 eV) will have the highest cutoff frequency, and the metal with the highest work function (platinum, 6.4 eV) will have the lowest cutoff frequency.

Conversely, the maximum wavelength of light needed to free electrons is directly related to the work function, so cesium will require the longest wavelength and platinum will require the shortest wavelength. When illuminated with 400 nm (3.10 eV) light, the kinetic energy of the emitted electrons will be the difference between the energy of the light and the work function, so cesium (with the smallest work function) will have the most energetic electrons, and metals with a work function larger than 3.10 eV (like aluminum, beryllium, and platinum) will not emit electrons at all.

Learn more about Work Function here:

https://brainly.com/question/12658742

#SPJ3

A circular coil has a 18.0 cm radius and consists of 25.0 closely wound turns of wire. An externally produced magnetic field of magnitude 3.00 mT is perpendicular to the coil. (a) If no current is in the coil, what magnetic flux links its turns?

Answers

Answer:

The magnetic flux links to its turns = [tex]7.6 \times10^{-3}[/tex] Wb.

Explanation:

Given :

Radius of circular coil = [tex]18 \times 10^{-2}[/tex] m

Number of turns = 25

Magnetic field = [tex]3 \times10^{-3}[/tex] T

Magnetic flux (Φ) is a measure of the magnetic field lines passes through a given area. The unit of magnetic flux is weber (Wb).

We know that,

⇒    Φ = [tex]BA[/tex]

Where [tex]B =[/tex] ext. magnetic field, [tex]A =[/tex] area of loop or coil.

But here given in question, we have turns of wire so our above eq. modified as follows.

⇒   Φ = [tex]NBA[/tex]

Where [tex]N =[/tex] no. of turns.

∴    Φ = [tex]25 \times 3 \times 10^{-3} \pi (18 \times10^{-2} )^{2}[/tex]

     Φ = [tex]7.6 \times 10^{-3} Wb[/tex]

Thus, the magnetic flux links to its turns = [tex]7.6 \times 10^{-3} Wb[/tex]

5. From Gauss’s law, the electric field set up by a uniform line of charge is E S 5 a l 2pP0r b r^ where r^ is a unit vector pointing radially away from the line and l is the linear charge density along the line. Derive an expression for the potential difference between r 5 r1 and r 5 r2.

Answers

Answer:

 ΔV = 2k λ ln (r₁ / r₂)

Explanation:

The electric potential is

         ΔV = - ∫ E. ds

The expression for the electric field of a charge line is given

           E = 2k λ / r

Let's replace and integrate

         ΔV = - 2k λ ∫ dr / r

         ΔV = -2 k λ ln r

Let's evaluate

       ΔV = - 2k λ ln r₂- ln r₁

       ΔV = -2k λ ln (r₂ / r₁)

       ΔV = 2k λ ln (r₁ / r₂)

A string of mass m is under tension, and the speed of a wave in the string is v. What will be the speed of a wave in the string if the mass of the string is increased to 2m but with no change in the length or tension?

A) v/ sq. rt. of 2
B) v/2
C) 2v
D) v * sq. rt. of 2
E) 4v

Answers

Answer:

A) v/ sq. rt. of 2

Explanation:

The speed of the wave in the string is defined as:

[tex]v=\sqrt{\frac{T}{\mu}}[/tex]

Where T is the tension on the string and [tex]\mu[/tex] is the linear density, that is, the mass per unit length:

[tex]\mu=\frac{m}{L}[/tex]

Where m is the mass of the string and L its length. We have [tex]m'=2m[/tex], [tex]T'=T[/tex] and [tex]L'=L[/tex]:

[tex]v'=\sqrt\frac{T'}{m'/L'}\\v'=\sqrt\frac{T}{2m/L}\\v'=\frac{1}{\sqrt2}\sqrt\frac{T}{m/L}\\v'=\frac{v}{\sqrt2}[/tex]

Explanation:

Below is an attachment containing the solution.

Consider the expression below. Assume m is an integer. 6m(2m + 18) Enter an expression in the box that uses the variable m and makes the equation true. (Simplify your answer completely. If no expression exists, enter DNE.)

Answers

6x2=12m
6x18=108
12m+108
Simplified: m+9 bc 12/12 and 108/12
Final answer:

The expression 6m(2m + 18) simplifies to 12m² + 108m. Therefore, the equivalent expression using the variable 'm' is 12m² + 108m.

Explanation:

The given expression is 6m(2m + 18). First, we distribute 6m across the terms in the parentheses, resulting in 12m² + 108m. So, an expression that uses the variable 'm' and makes the equation true when the given expression is simplified would be 12m² + 108m. This answer is fully simplified, and the variable 'm' is assumed to be an integer.

The expression 6m(2m + 18) simplifies to 12m² + 108m. Therefore, the equivalent expression using the variable 'm' is 12m² + 108m.

Learn more about Simplifying expressions here:

https://brainly.com/question/403991

#SPJ2

A real battery with internal resistance 0.460 Ω and emf 9.00 V is used to charge a 56.0-µF capacitor. A 21.0-Ω resistor is put in series with the battery and the capacitor when charging. (a) What is the time constant for this circuit?

Answers

Answer: 1.176×10^-3 s

Explanation: The time constant formulae for an RC circuit is given below as

t =RC

Where t = time constant , R = magnitude of resistance = 21 ohms , C = capacitance of capacitor = 56 uf = 56×10^-6 F

t = 56×10^-6 × 21

t = 1176×10^-6

t = 1.176×10^-3 s

Given Information:

Internal resistance of battery = 0.460

Resistance = 21.0 Ω

Capacitance = 56.0 µF

Required Information:

time constant = τ = ?

Answer:

τ = 0.0012

Explanation:

The time constant τ provides the information about how long it will take to charge the capacitor up to certain level.

τ = Req*C

Where Req is the equivalent resistance and C is the capacitance.

Req = R + r

Where R is the resistance of the resistor and r is the internal resistance of the battery.

Req = 21.0 + 0.460 = 21.460 Ω

τ = Req*C

τ = 21.46*56x10⁻⁶

τ = 0.0012

A capacitor approximately charges to 63% in one τ and about 99% in 5τ

On the​ moon, all​ free-fall distance functions are of the form​s(t)=0.81t^2 where t is in seconds and s is in meters. An object is dropped from a height of 200


meters above the moon. After 9 sec, consider parts​ (a) through​(d) below.


​a)


How far has the object​ fallen?


​b)


How fast is it​ traveling?


​c)


What is its​ acceleration?


​d)


Explain the meaning of the second derivative of this​ free-fall function.

Answers

Final answer:

After 9 seconds, an object dropped on the moon will have fallen 65.61 meters, be traveling at 14.58 meters per second, with an acceleration of 1.62 meters per second squared. The second derivative of the distance function represents the moon's gravitational acceleration.

Explanation:

An object is dropped on the moon from a height of 200 meters, and the distance function of free-fall due to lunar gravity is given by s(t)=0.81t^2. We are asked to determine various properties of the object's motion after 9 seconds.

a) Distance Fallen

To find how far the object has fallen, we plug t=9 into the distance function to get s(9)=0.81(9)^2=65.61 meters. This is the distance the object has fallen, not the distance from its starting height.

b) Velocity

The object's velocity can be determined by finding the derivative of the distance function, which gives us v(t) = 2(0.81)t = 1.62t. Substituting t=9, we find v(9) = 1.62(9) = 14.58 meters per second.

c) Acceleration

The acceleration of the object is constant and equal to twice the coefficient of t^2 in the distance function, which is 1.62 meters per second squared on the moon.

d) Meaning of the Second Derivative

The second derivative of the free-fall distance function represents the acceleration due to gravity on the moon. It's constant at 1.62 meters per second squared, indicating uniform acceleration during free-fall.

A segment of wire carries a current of 25 A along the x axis from x = −2.0 m to x = 0 and then along the y axis from y = 0 to y = 3.0 m. In this region of space, the magnetic field is equal to 40 mT in the positive z direction. What is the magnitude of the force on this segment of wire?

Answers

Final answer:

The magnitude of force on the wire segment along the y-axis is 3.0N and directed along the negative x-axis, while there's no force on the segment along the x-axis.

Explanation:

To find the magnitude of the force on the wire, we can use the formula F = I * (L x B), where F is the magnetic force, I is the current, L is the length vector of the wire segment, and B is the magnetic field. The force will be perpendicular to both the current direction and the magnetic field direction, according to the right-hand rule.

The wire is in two segments, one along the x-axis and one along the y-axis. First, we calculate the force on the section of the wire along the x-axis: Fx = I * Lx * B, which is 0 since the magnetic field is in the z-direction and Lx is in the x-direction, making the angle between them 90 degrees. So, there's no force for this segment.

Second, we calculate the force on the section of the wire along the y-axis: Fy = I * Ly * B. The force experienced by this segment can be calculated using the formula with the values provided (I=25A, Ly=3.0m, B=40mT). Therefore, Fy = 25A * 3.0m * 40mT = 3000mN or 3.0N, which will be directed along the negative x-axis, under the right-hand rule.

A couple is defined as two parallel forces, separated by a distance, that have equal magnitudes but opposite directions. A couple only produces a rotation in a specified direction. The moment produced by a couple is called a couple moment.
A submarine hatch door is to be opened by applying two oppositely oriented forces of equal magnitude F=265N at points A and B on the hatch door wheel. The radii of the wheel's inner and outer rings are r1 = 0.470 m and r2 = 0.200 m, respectively.
Calculate the moments MA and MB about point D for the forces applied at points A and B. Then, determine the resulting couple moment MR. Assume that a positive moment produces a counterclockwise rotation whereas a negative moment produces a clockwise rotation.

Answers

Answer:

MA = 178 Nm

MB = 72 Nm

MR = 249 Nm

For the moments MA the lever arm was taken as r1 + r2 which is the distance of the point of application of the force at point A to point D.

For the moment MB, the distance of the point of application of force is r1 - r2 which is the distance from the outer ring to the inner ring.

The couple moment is given by F × r1. Which is basically a sum of the moments of both forces applied on the wheel.

Explanation:

See the attachment for detail of the calculation.

Final answer:

The moment MA for the force at point A is 124.55 N*m, the moment MB for the force at point B is 53 N*m, and the resulting couple moment MR is 71.55 N*m.

Explanation:

To calculate the moments MA and MB about point D for the forces applied at points A and B, we can use the formula:

M = F * r

Where M is the moment, F is the force, and r is the radius. For point A, the radius is r1 = 0.470 m and the force is F = 265 N. So, MA = 265 N * 0.470 m = 124.55 N*m (counterclockwise).

Similarly, for point B, the radius is r2 = 0.200 m and the force is F = 265 N. So, MB = 265 N * 0.200 m = 53 N*m (clockwise).

To determine the resulting couple moment MR, we can subtract the clockwise moment (MB) from the counterclockwise moment (MA). MR = MA - MB = 124.55 N*m - 53 N*m = 71.55 N*m (counterclockwise).

Learn more about moment here:

https://brainly.com/question/32684372

#SPJ3

A steel cable supports an actor as he swings onto the stage. The weight of the actor stretches the steel cable. To describe the relationship between stress and strain for the steel cable, you would use:

a. both shear modulus and bulk modulus.
b. Young's modulus
c. bulk modulus.
d. shear modulus
e. both Young's modulus and bulk modulus.

Answers

Answer:

Option (b)

Explanation:

As the actor swings on a steel cable, the cable stretches due to the weight of the actor. So, the stress produced by the weight of the actor is longitudinal stress and the strain is also longitudinal in nature.

The modulus of elasticity associated to the normal stress and the longitudinal strain is young's modulus.

After the NEAR spacecraft passed Mathilde, on several occasions rocket propellant was expelled to adjust the spacecraft's momentum in order to follow a path that would approach the asteroid Eros, the final destination for the mission. After getting close to Eros, further small adjustments made the momentum just right to give a circular orbit of radius 45 km (45 × 103 m) around the asteroid. So much propellant had been used that the final mass of the spacecraft while in circular orbit around Eros was only 550 kg. The spacecraft took 1.04 days to make one complete circular orbit around Eros. Calculate what the mass of Eros must be.

Answers

Answer:

[tex]6.68\times 10^{15}\ kg[/tex]

Explanation:

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

R = Radius of orbit = 45 km

T = Time period = 1.04 days

Mass of Eros would be given by the following equation

[tex]M=\dfrac{4\pi^2R^3}{GT^2}\\\Rightarrow M=\dfrac{4\pi^2\times (45\times 10^3)^3}{6.67\times 10^{-11}\times (1.04\times 24\times 3600)^2}\\\Rightarrow M=6.68\times 10^{15}\ kg[/tex]

The mass of Eros is [tex]6.68\times 10^{15}\ kg[/tex]

A 37 cm long solenoid, 1.8 cm in diameter, is to produce a 0.50 T magnetic field at its center. If the maximum current is 4.4 A, how many turns must the solenoid have? Express your answer using two significant figures.

Answers

Answer:

33,458.71 turns

Explanation:

Given: L = 37 cm = 0.37 m, B= 0.50 T, I = 4.4 A, n= number of turn per meter

μ₀ = Permeability of free space = 4 π × 10 ⁻⁷

Solution:

We have B = μ₀ × n × I

⇒ n = B/ (μ₀ × I)

n = 0.50 T / ( 4 π × 10 ⁻⁷ × 4.4 A)

n = 90,428.94 turn/m

No. of turn through 0.37 m long solenoid = 90,428.94 turn/m × 0.37

= 33,458.71 turns

Given Information:  

Diameter of solenoid = d = 1.8 cm = 0.018 m

Length of solenoid = L = 37 cm = 0.37 m

Current = I = 4.4 A  

Magnetic field = B = 0.50 T  

Required Information:  

Number of turns = N = ?  

Answer:  

Number of turns ≈ 33,498 or 33,458

Step-by-step explanation:  

The magnetic field at the center of the solenoid is given by

B = μ₀NI/√ (L²+4r²)

N = B√ (L²+4r²)/μ₀I

Where L is the length and r is the radius of the solenoid, N is the number of turns and B is the magnetic field.

r = d/2 = 0.018/2 = 0.009 m

N = 0.50√ (0.37)²+(4*0.009²)/4πx10⁻⁷*4.4

N ≈ 33,498 Turns

Please note that we can also use a more simplified approximate model for this problem since the length of the solenoid is much greater than the radius of the solenoid

L = 0.37 >> r = 0.009

The approximate model is given by

B = μ₀NI/L

N = BL/μ₀I

N = 0.50*0.37/4πx10⁻⁷*4.4

N ≈ 33,458 Turns

As you can notice the results with the approximate model are very close to the exact model.

The inner and outer surfaces of a cell membrane carry a negative and positive charge respectively. Because of these charges, a potential difference of about 70 mV exists across the membrane. The thickness of the membrane is 8 nm. If the membrane were empty (filled with air), what would the magnitude of the electric field inside the membrane

Answers

Answer:

The magnitude of the electric field inside the membrane is 8.8×10⁶V/m

Explanation:

The electric field due to electric potential at a distance Δs is given by

E=ΔV/Δs

We have to find the magnitude electric field in the membrane

Ecell= -ΔV/Δs

[tex]E_{cell}=-\frac{V_{in}-V_{out}}{s} \\E_{cell}=\frac{V_{out}-V_{in}}{s}\\E_{cell}=\frac{0.070V}{8*10^{-9}m } \\E_{cell}=8.8*10^{6}V/m[/tex]

The magnitude of the electric field inside the membrane is 8.8×10⁶V/m

The magnitude of the electric field inside the membrane, if it were empty, would be approximately [tex]\( 8.75 \times 10^6 \) V/m.[/tex]

To find the magnitude of the electric field inside the membrane, we can use the formula for electric field strength ( E ) due to a uniform field between two parallel plates, which is given by:

[tex]\[ E = \frac{V}{d} \][/tex]

where ( V ) is the potential difference across the plates (in volts) and ( d ) is the separation between the plates (in meters). In this case, the potential difference ( V ) is given as 70 mV, which we need to convert to volts:

[tex]\[ V = 70 \text{ mV} = 70 \times 10^{-3} \text{ V} \][/tex]

The thickness of the membrane ( d ) is given as 8 nm, which we need to convert to meters:

[tex]\[ d = 8 \text{ nm} = 8 \times 10^{-9} \text{ m} \][/tex]

Now we can plug these values into the formula for the electric field:

[tex]\[ E = \frac{70 \times 10^{-3} \text{ V}}{8 \times 10^{-9} \text{ m}} \][/tex]

[tex]\[ E = \frac{70}{8} \times 10^{(3 - (-9))} \text{ V/m} \][/tex]

[tex]\[ E = 8.75 \times 10^{6} \text{ V/m} \][/tex]

After your school's team wins the regional championship, students go to the dorm roof and start setting off fireworks rockets. The rockets explode high in the air and the sound travels out uniformly in all directions. If the sound intensity is 1.97 10-6 W/m2 at a distance of 113 m from the explosion, at what distance from the explosion is the sound intensity half this value?

Answers

Answer:

160 m

Explanation:

The intensity, I, of the sound is inversely proportional to the square of the distance, r, from the source.

[tex]I\propto \dfrac{1}{r^2}[/tex]

Hence,

[tex]I_1r_1^2 = I_2r_2^2[/tex]

[tex]r_2 = r_1\sqrt{\dfrac{I_1}{I_2}}[/tex]

From the question, [tex]I_2[/tex] is half of [tex]I_1[/tex]

[tex]r_2 = r_1\sqrt{\dfrac{I_1}{0.5I_1}}[/tex]

[tex]r_2 = r_1\sqrt{2}[/tex]

[tex]r_2 = 113\text{ m}\sqrt{2} = 160 \text{ m}[/tex]

Answer:

Distance ,d= 159.81m

Explanation:

The intensity, I, of the sound is inversely proportional to the square of the distance, d,from the source.

Using the equation d/do=sqrt2

d= dosqrt2

Where d=113m

d= 113sqrt2

d= 159.81m

A rod of length L has a charge Q uniformly distributed along its length. The rod lies along the y axis with one end at the origin. (a) Find an expression for the electric potential as a function of position along the x axis.

Answers

Answer:

 V = k Q/l  ln [(l +√(l² + x²)) / x]

Explanation:

The electrical potential for a continuous distribution of charges is

      V = k ∫ dq / r

Let's apply this expression to our case, define a linear charge density for the bar

           λ = dq / dy

          dq = λ dy

The distance from a point on the bar to the x-axis is

            r = √ (x² + y²)

Let's replace

          V = K ∫ λ dy /√ (x² + y²)

     

We integrate

         V = k λ ln (y + √ (x² + y²))

       

Let's evaluate between y = 0 and y = l

         V = k λ [ ln (l +√(x² + l²) - ln x]

We substitute the linear density

           V = k Q/l  ln [(l +√(l² + x²)) / x]

Final answer:

To calculate the electric potential at a point on the x-axis due to a uniformly charged rod, we use the concept of charge density and integrate the contributions from each infinitesimal charge element along the rod with respect to the position.

Explanation:

The student is asking about the electric potential due to a uniformly charged rod on the x-axis. To find an expression for the electric potential at a point on the x-axis, we can imagine dividing the rod into infinitesimally small segments of charge dq. Given that the charge Q is evenly distributed along the rod of length L, the linear charge density λ is Q/L. The potential dV due to a small element dq at a distance x from the rod is given by Coulomb's law as dV = k * dq / r, where k is Coulomb's constant and r is the distance from the charge element to the point on the x-axis.

To find the total potential V, we integrate this expression from one end of the rod to the other. The distance r varies along the rod, so we integrate with respect to y, the position along the rod. Setting up the integral, we have V = k * ∫_{-L/2}^{L/2} (dq / √((L/2 - y)^2 + x^2)) where the limits of integration account for the rod's position along the y-axis with one end at the origin and λ = Q/L. After substituting dq with λdy, performing the integration, and simplifying, we obtain the electric potential V(x) as a function of position along the x-axis.

A bicycle is rolling down a circular portion of a path; this portion of the path has a radius of 9.30 m. As the drawing illustrates, the angular displacement of the bicycle is 1.130 rad. What is the angle (in radians) through which each bicycle wheel (radius = 0.300 m) rotates?

Answers

Answer:

The angle through which each bicycle wheel rotates is 35.03 rad.

Explanation:

Given;

the radius of the circular path, R = 9.30 m

the angular displacement of the bicycle, θ = 1.130 rad

the radius of the bicycle wheel, r = 0.3

S = θR

where;

s is the distance of the circular path

S = 1.13 x 9.3 = 10.509 m

The angle (in radians) through which each bicycle wheel of radius 0.300 m rotates is given as;

θr = 10.509 m

θ = 10.509 / 0.3

θ = 35.03 rad.

Therefore, the angle through which each bicycle wheel of radius 0.300 m rotates is 35.03 rad.

A simply supported wood beam with a span of L = 15 ft supports a uniformly distributed load of w0 = 270 lb/ft. The allowable bending stress of the wood is 1.95 ksi. If the aspect ratio of the solid rectangular wood beam is specified as h/b = 1.75, calculate the minimum width b that can be used for the beam.

Answers

The minimum width b that can be used for the beam is 4.32 in

To determine the minimum width (b) of the solid rectangular wood beam, we employ principles of structural engineering.

The maximum bending moment (M) for a simply supported beam with a uniformly distributed load (\(w_0\)) occurs at the center and is given by [tex]\(M = \frac{w_0 L^2}{8}\).[/tex]

The section modulus (S) for a rectangular cross-section is [tex]\(S = \frac{b \times h^2}{6}\).[/tex]

The bending stress (\(σ_b\)) is given by[tex]\(σ_b = \frac{M}{S}\)[/tex].

Setting \(σ_b\) equal to the allowable bending stress [tex](\(1.95 \, \text{ksi}\))[/tex]and using the specified aspect ratio (h/b = 1.75), we can solve for b.

This ensures that the wood beam meets structural safety criteria.

The calculation yields a minimum width b of 4.32 in, ensuring that the beam is structurally sound, withstanding the specified uniformly distributed load and adhering to the aspect ratio constraint in compliance with the allowable bending stress.

Star #1 is approaching the Earth with speed v. Star #2 is receding from the Earth with the same speed v. Measurements of the same spectral line from each of the stars show Doppler shifts in frequency. The light from which star will have the larger magnitude shift in frequency? a. star #1 b. Both stars will have the same shift. c. The value of the speed must be known before an answer can be found. d. star #2

Answers

Answer:

b. Both stars will have the same shift.

Explanation:

It's a very simple problem to solve. Star 1 is approaching toward Earth with a speed v, so let's assume that the change in Doppler Shift is +F and Star 2 is moving away so the change in Doppler shift is -F. But it's time to notice the speed of both stars and that is same but only directions are different. speed is the main factor here. The magnitude of both shifts is F as we can see and + and - are showing there direction of motion. So, because of same amount of speed, both stars will have same shift magnitude. (Just the directions are different)

The surface of the dock is 6 feet above the water. If you pull the rope in at a rate of 2 ft/sec, how quickly is the boat approaching the dock at the moment when there is 10 feet of rope still left to pull in

Answers

Answer:

The boat is approaching the dock at a rate of 2.5 ft/s.

Explanation:

Let the rope length be 'l' at any time 't', the distance of boat from dock be 'b' at any time 't'.

Given:

The height of dock above water (h) = 6 feet

Rate of pull of rope or rate of change of rope is, [tex]\frac{dl}{dt}=2\ ft/s[/tex]

As clear from the question, the height is fixed and only the length 'l' and distance 'b' varies with time 't'.

Now, the above situation represents a right angled triangle as shown below.

Using Pythagoras Theorem, we have:

[tex]l^2=h^2+b^2\\\\l^2=6^2+b^2\\\\l^2=36+b^2----------(1)[/tex]

Now, differentiating the above equation with time 't', we get:

[tex]2l\frac{dl}{dt}=0+2b\frac{db}{dt}\\\\l\frac{dl}{dt}=b\frac{db}{dt}\\\\\frac{db}{dt}=\frac{l}{b}\frac{dl}{dt}------(2)[/tex]

Now, the distance 'b' can be calculated using 'l=10 ft' in equation (1). This gives,

[tex]b^2=10^2-36\\\\b=\sqrt{64}=8\ ft[/tex]

Now, substituting all the given values in equation (2) and solve for [tex]\frac{db}{dt}[/tex]. This gives,

[tex]\frac{db}{dt}=\frac{10}{8}\times 2\\\\\frac{db}{dt}=2.5\ ft/s[/tex]

Therefore, the boat is approaching the dock at a rate of 2.5 ft/s.

In a series RCL circuit the generator is set to a frequency that is not the resonant frequency. This nonresonant frequency is such that the ratio of the inductive reactance to the capacitive reactance of the circuit is observed to be 5.68. The resonant frequency is 240 Hz. What is the frequency of the generator

Answers

Answer:

Explanation:

Resonant frequency is 240

4π² x 240² = 1 / LC

230400π² = 1 / LC

Let the required frequency = n

inductive reactance = 2 πn L

capacitative reactance = 1 /  2 π n C

inductive reactance / capacitative reactance

= 4π² x n ² x LC = 5.68

4π² x n ² = 1 / LC x 5.68

= 230400π²  x 5.68

4n ²= 230400 x 5.68

n ²= 57600 x 5.68

n ² = 327168

n = 572 approx

The generator's frequency in this RLC circuit, where the ratio of inductive to capacitive reactance is 5.68 and the resonant frequency is 240 Hz, is approximately 571 Hz.

To solve this problem, we need to use the relationship between inductive and capacitive reactance in an RLC circuit. Given that the ratio of the inductive reactance (XL) to the capacitive reactance (XC) is 5.68,

X_L / X_C = 5.68

Reactance is frequency-dependent, with the following formulas for inductive and capacitive reactance:

X_L = 2πfLX_C = 1 / (2πfC)

Given the resonant frequency as 240 Hz, we start by calculating the resonance reactances:

At resonance: X_L = X_C, so 2π(240)L = 1 / (2π(240)C)

Using the non-resonant frequency, we use the reactance ratio:

2πfL / (1 / (2πfC)) = 5.68

Rearranging gives us:

f² = 5.68 / (2π)²(LC)

Since 240 Hz is the resonant frequency, substituting f:

f² = 5.68 * (240)²

Simplifying yields:

f = 240 * √(5.68)f ≈ 571 Hz

Therefore, the generator frequency is approximately 571 Hz.

In each case the momentum before the collision is: (2.00 kg) (2.00 m/s) = 4.00 kg * m/s

1. In each of the three cases above show that momentum is conserved by finding the total momentum after the collision.
2. In each of the three cases, find the kinetic energy lost and characterize the collision as elastic, partially inelastic, or totally inelastic. The kinetic energy before the collision is (1/2)(2.00 kg)(2.00 m/s)^2 = 4.00 kg * m^2/s^2 = 4.00 J.

3. An impossible outcome of such a collision is that A stocks to B and they both move off together at 1.414 m/s. First show that this collision would satisfy conservation of kinetic energy and then explain briefly why it is an impossible result.

Answers

Answer:

Check Explanation.

Explanation:

Momentum before collision = (2)(2) + (2)(0) = 4 kgm/s

a) Scenario A

After collision, Mass A sticks to Mass B and they move off with a velocity of 1 m/s

Momentum after collision = (sum of the masses) × (common velocity) = (2+2) × (1) = 4 kgm/s

Which is equal to the momentum before collision, hence, momentum is conserved.

Scenario B

They bounce off of each other and move off in the same direction, mass A moves with a speed of 0.5 m/s and mass B moves with a speed of 1.5 m/s

Momentum after collision = (2)(0.5) + (2)(1.5) = 1 + 3 = 4.0 kgm/s

This is equal to the momentum before collision too, hence, momentum is conserved.

Scenario C

Mass A comes to rest after collision and mass B moves off with a speed of 2 m/s

Momentum after collision = (2)(0) + (2)(2) = 0 + 4 = 4.0 kgm/s

This is equal to the momentum before collision, hence, momentum is conserved.

b) Kinetic energy is normally conserved in a perfectly elastic collision, if the two bodies do not stick together after collision and kinetic energy isn't still conserved, then the collision is termed partially inelastic.

Kinetic energy before collision = (1/2)(2.00)(2.00²) + (1/2)(2)(0²) = 4.00 J.

Scenario A

After collision, Mass A sticks to Mass B and they move off with a velocity of 1 m/s

Kinetic energy after collision = (1/2)(2+2)(1²) = 2.0 J

Kinetic energy lost = (kinetic energy before collision) - (kinetic energy after collision) = 4 - 2 = 2.00 J

Kinetic energy after collision isn't equal to kinetic energy before collision. This collision is evidently totally inelastic.

Scenario B

They bounce off of each other and move off in the same direction, mass A moves with a speed of 0.5 m/s and mass B moves with a speed of 1.5 m/s

Kinetic energy after collision = (1/2)(2)(0.5²) + (1/2)(2)(1.5²) = 0.25 + 3.75 = 4.0 J

Kinetic energy lost = 4 - 4 = 0 J

Kinetic energy after collision is equal to kinetic energy before collision. Hence, this collision is evidently elastic.

Scenario C

Mass A comes to rest after collision and mass B moves off with a speed of 2 m/s

Kinetic energy after collision = (1/2)(2)(0²) + (1/2)(2)(2²) = 4.0 J

Kinetic energy lost = 4 - 4 = 0 J

Kinetic energy after collision is equal to kinetic energy before collision. Hence, this collision is evidently elastic.

c) An impossible outcome of such a collision is that A stocks to B and they both move off together at 1.414 m/s.

In this scenario,

Kinetic energy after collision = (1/2)(2+2)(1.414²) = 4.0 J

This kinetic energy after collision is equal to the kinetic energy before collision and this satisfies the conservation of kinetic energy.

But the collision isn't possible because, the momentum after collision isn't equal to the momentum before collision.

Momentum after collision = (2+2)(1.414) = 5.656 kgm/s

which is not equal to the 4.0 kgm/s obtained before collision.

This is an impossible result because in all types of collision or explosion, the second law explains that first of all, the momentum is always conserved. And this evidently violates the rule. Hence, it is not possible.

Sound with frequency 1240 Hz leaves a room through a doorway with a width of 1.13 m . At what minimum angle relative to the centerline perpendicular to the doorway will someone outside the room hear no sound? Use 344 m/s for the speed of sound in air and assume that the source and listener are both far enough from the doorway for Fraunhofer diffraction to apply. You can ignore effects of reflections. Express your answer in radians.

Answers

Given Information:

frequency = 1240 Hz

width = a = 1.13 m

speed of sound = c = 344 m/s

Required Information:

angle = θ = ?

Answer:

θ = 14.18 rad

Explanation:

We can find out the angle relative to the centerline perpendicular to the doorway by using the following relation

sin(θ) = λ/a

Where λ is the wavelength of the sound wave and a is width

λ = c/f

Where c is the speed of the sound and f is the frequency

λ = 344/1240

λ = 0.277

sin(θ) = λ/a

θ =sin⁻¹(λ/a)

θ =sin⁻¹(0.277/1.13)

θ =sin⁻¹(0.277/1.13)

θ = 14.18 rad

For a two-level system, the weight of a given energy distribution can be expressed in terms of the number of systems, N, and the number of systems occupying the excited state, n1. What is the expression for weight in terms of these quantities

Answers

Answer:

W = N!/(n0! * n1!)

Explanation:

Let n0 = number of particles in the lowest energy state

n1 = number of particles in the excited energy state.

Using this, we can say that N = n0 + n1

From this we can then express the weight, W of the close system by finding the factorials of each particles

W = N!/(n0! * n1!)

Hence, the weight W is expressed as W = N!/(n0! * n1!)

High-altitude mountain climbers do not eat snow, but always melt it first with a stove. To see why, calculate the energy absorbed from a climber's body under the following conditions. The specific heat of ice is 2100 J/kg⋅C∘, the latent heat of fusion is 333 kJ/kg, the specific heat of water is 4186 J/kg⋅C∘

Answers

Answer:

The conditions are not given in the question. Here is the complete question.

High-altitude mountain climbers do not eat snow, but always melt it first with a stove. To see why, calculate the energy absorbed from a climber's body under the following conditions. The specific heat of ice is 2100 J/kg⋅C∘, the latent heat of fusion is 333 kJ/kg, the specific heat of water is 4186 J/kg⋅C∘

a) eat 1.0kg of -15 degrees Celsius snow which your body warms to body temperature of 37 degrees Celsius ?

b) melt 1.0kg of -15 degrees Celsius snow using a stove and drink the resulting 1.0kg of water at 2 degrees Celsius, which your body has to warm to 37 degrees Celsius ?

Explanation:

Let's calculate the heat required to convert ice from -15°C to 0°C and then the heat required to convert it into the water.

a)

Heat required to convert -15°C ice to 0°C.

  [tex]ms_{ice}[/tex]ΔT = (1.0)(2.100×10³)(15) = 3.150×[tex]10^{4}[/tex]J

Heat required to convert 1.0 kg ice to water.

    [tex]mL_{ice} = 1[/tex]×[tex]3.33[/tex]×[tex]10^{5}[/tex] = 3.33×[tex]10^{5}[/tex]J

Heat required to convert 1.0 kg water at 0°C to 37°C.

   [tex]ms_{water}[/tex]ΔT = 1×4.186×[tex]10^{3}[/tex]×37 = 1.548×[tex]10^{5}[/tex] J

Total heat required = 3.150×[tex]10^{4}[/tex] + 3.33×[tex]10^{5}[/tex] + 1.548×[tex]10^{5}[/tex]

                              = 5.19×[tex]10^{5}[/tex] J

b)

Heat required to warm 1.0 kg water at 2°C to water at 37°C.

[tex]ms_{water}[/tex]ΔT = 1×4.186×[tex]10^{3}[/tex]×35

                = 1.465×[tex]10^{5}[/tex]J

   

Final answer:

At the start of meiosis II, the cell exhibits characteristics of a haploid cell preparing for mitosis. It has one set of homologous chromosomes, each with two chromatids, equivalent to a haploid cell in the G₂ phase of interphase.

Explanation:

At the beginning of meiosis II, a cell appears much like a haploid cell preparing to undergo mitosis. After completion of meiosis I, the cell does not duplicate its chromosomes, so at the onset of meiosis II, each dividing cell has only one set of homologous chromosomes, each with two chromatids. This results in half the number of sister chromatids to separate out as a diploid cell undergoing mitosis. In terms of chromosomal content, cells at the start of meiosis II are similar to those of haploid cells in the G₂ phase of interphase, where they are preparing for mitosis.

Learn more about Meiosis II here:

https://brainly.com/question/10621150

#SPJ3

Two protons are released from rest when they are 0.750 {\rm nm} apart.

a) What is the maximum speed they will reach?

b) What is the max acceleration they will reach?

Answers

Explanation:

Given:

m = 1.673 × 10^-27 kg

Q = q = 1.602 × 10^-19 C

r = 0.75 nm

= 0.75 × 10^-9 m

A.

Energy, U = (kQq)/r

Ut = 1/2 mv^2 + 1/2 mv^2

1.673 × 10^-27 × v^2 = (8.99 × 10^9 × (1.602 × 10^-19)^2)/0.75 × 10^-9

v = 1.356 × 10^4 m/s

B.

F = (kQq)/r^2

F = m × a

1.673 × 10^-27 × a = ((8.99 × 10^9 × (1.602 × 10-19)^2)/(0.075 × 10^-9)^2

a = 2.45 × 10^17 m/s^2.

An electron moving at4.00 × 103m/sin a 1.25-Tmagnetic field experiences a magnetic force of1.40 × 10−16N.What angle does the velocity of theelectron make with the magnetic field? There are twoanswers

Answers

Answer:

Explanation:

velocity of electron V = 4 x 10³ m/s

magnetic field B = 1.25 T .

magnetic force = 1.4 x 10⁻¹⁶ N.

If direction of velocity makes angle θ with magnetic field

magnetic force = magnetic field x charge on electron x velocity x sinθ

1.4 x 10⁻¹⁶ = 1.25 x 1.6 x 10⁻¹⁹ x 4 x 10³ x sinθ

1.4 x 10⁻¹⁶ = 8  x 10⁻¹⁶ x sinθ

sinθ  = 1.4 / 8

= .175

θ = 10 degree

or 180 - 10

= 170 degree

because

sinθ = sin (180 - θ)

A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a horizontal circle whose diameter is 1.0 m. What is the magnitude of the net force on the ball

Answers

Answer:

F = 100.0 N

Explanation:

in order to the ball keeps moving at a constant speed in a circle, instead of moving along a straight line, there must be an acceleration that accounts for the change in direction of the ball.This acceleration, called centripetal, is directed at any time, towards the center of the circle.As any acceleration, as dictated by Newton's 2nd law, it must be produced by a force, called centripetal force.The magnitude of this force is related with the mass, the speed and the radius of the circle, as follows:

       [tex]F_{c} = m *\frac{v^{2} }{r} = 2.0 kg *\frac{(5.0m/s)^{2} }{0.5m} =100.0 N[/tex]

The magnitude of the net force on the ball is  100.0 N
Answer:

100.0N

Explanation:

As the ball moves round the circle, a centripetal acceleration which is directed towards the center of the circle will keep the ball from falling off. This acceleration produces a force called centripetal force (F).

Since this is the only force acting on the ball, then the net force acting on the ball to keep it moving round the circle is the centripetal force.

F = m a         [according to Newton's second law of motion]    --------------(i)

Where;

m = mass of the ball.

a = centripetal acceleration. = [tex]\frac{v^2}{r}[/tex]

v = speed of the ball.

r = radius of the circle.

Substitute a = [tex]\frac{v^2}{r}[/tex] into equation (i) as follows;

F = m x [tex]\frac{v^2}{r}[/tex]      --------------------(ii)

From the question;

m = 2.0kg

v = 5.0m/s

r = diameter / 2     [diameter = 1.0m]

r = 1.0 / 2

r = 0.5m

Substitute these values into equation (ii) as follows;

F = 2.0 x [tex]\frac{5.0^{2} }{0.5}[/tex]

F = 2.0 x [tex]\frac{25.0}{0.5}[/tex]

F = 2.0 x 50.0

F = 100.0N

Therefore, the magnitude of the net force on the ball is 100.0N

Other Questions
What is the correct answer to number 9? Please explain step by step. Why did African Americans who moved to northern cities still face limitationsbecause of their race?OA. Their families were too large and caused overcrowding in cities.B. The Reconstruction Amendments only applied to states in theSouthOC. There were no laws against limiting housing or jobs to AfricanAmericans.OD. Northerners did not like that they could not speak more than onelanguage.SUBMIT How do you writer this function in standard form?? In prophase I of meiosis, crossing over results in Seventy independent messages are sent from an electronic transmission center.Messages are processed sequentially, one after another. Transmission time of each message is Exponential with parameter = 5 min1. Find the probability that all 70 messages are transmitted in less than 12 minutes. Use the Central Limit Theorem. What are small distal branches of an axon Examine the four skeletons.Indicate which species appears to be bestadapted for swimming underwater for a longtime. Which characters allow the animal tobehave this way? Which major type of advertising is used to communicate a message on behalf of some good cause, such as stopping drug abuse, and is usually created by advertising professionals free of charge with the necessary time and space often donated by the media What is the area of this figure? A user is unable to install virtualization software on a Windows 8.1 computer. The user verified the host has sufficient RAM, plenty of available free disk space, and a multicore processor.Which of the following is the most likely cause for this behavior?a. Windows 8.1 does not support Type 2 hypervisors.b. The motherboard does not support hardware-assisted virtualization.c. The user does not have a valid product license key.d. The system is incompatible with Type 1 hypervisors. Find the volume of a cylinder if the radius is 12 inches and the height is 17 inches Solve for xxx. Your answer must be simplified. -30 A local pizza parlor located on campus offers a student rate for its pizza lunch special. This is a form of __________. a. predatory pricing and is legal. b. predatory pricing and is illegal. c. bait-and-switch pricing and is legal. d. price discrimination and is illegal. e. price discrimination and is legal. The focal points of an ellipse are (12, 0) and (12, 0), and the point (12, 7) is on the ellipse. Find the points where this curve intersects the coordinate axes. Danny "Dimes" Donahue is a neighborhoods 9-year-old entrepreneur. His most recent venture is selling homemade brownies that he bakes himself. At a price of $2.75 each, he sells 250. At a price of $2.25 each, he sells 300. A. What is the elasticity of demand?B. Is demand elastic or inelastic over this price range?C. If demand had the same elasticity for a price decline from $2.25 to $1.75 as it does for the decline from $2.75 to $2.25, would cutting the price from $2.25 to $1.75 increase or decrease Danny's total revenue? I THINK ITS D OR B? NOT SURE, CORRECT ME IF WRONG PLEASE, TIA!Progressive Era reformers after 1900 sought federal laws to regulate working conditions and to set a minimum age for child workers. The need for these laws was prompted by which of the following? A) unions restricting membership to adults only?B) civil war casualties leading to children taking the jobs of adults?C) lack of job opportunities for children seeking after school jobs?D) industrialists using child labor to keep production costs low? I have placed my happiness on seeing you good and accomplished; and no distress which this world can now bring on me would equal that of your disappointing my hopes.What is the connotative effect of the word distress on Jefferson's tone in this letter? A) The word "distress" does not show any particular concern or worry on Jefferson's part for his daughter's education. B)It shows how deeply and seriously Jefferson wants his daughter to take her education--because his love for her depends upon it. C)Jefferson is using the word primarily to create a joking or teasing tone with his daughter that is evident throughout the entire passage. D)It shows that Jefferson is more concerned with his daughter being happy or carefree than he is worried about her education and studying all the time. You can be jailed up to six months and fined up to $1,000 if you _________________. A. are convicted of being a habitual truant from school B. abandon or dump an animal on the road C. drive faster than the posted speed limit Simplify the following expression.2x^5+ 3x^3 - 5x^2 + x^2 +7x+1+7x^5 - 3x^3 - 4 What is this please help