William WangHomework #33 Regents Review (3)0989Assignment Mode : Open (Time On Task) 9 of 25 ListenDuring a collision, an 84-kilogram driver of a car moving at 24 meters per second is brought to rest by an inflating air bag in 1.2 seconds. The magnitude of the force exerted on the driver by the air bag is approximately7.0 × 101 N8.2 × 102 N1.7 × 103 N2.0 × 103 NTime on question: 00:02:59

Explanation:

The half-life [tex]h[/tex] of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.

In this case, we are given the half life of two elements:

beryllium-13: [tex]h_{B-13}=5(10)^{-10}s=0.0000000005s[/tex]

beryllium-15: [tex]h_{B-15}=2(10)^{-7}s=0.0000002s[/tex]

As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?

We can find it out by the following expression:

[tex]h_{B-15}=X.h_{B-13}[/tex]

Where [tex]X[/tex] is the amount we want to find:

[tex]X=\frac{h_{B-15}}{h_{B-13}}[/tex]

[tex]X=\frac{2(10)^{-7}s}{5(10)^{-10}s}[/tex]

Finally:

[tex]X=400[/tex]

Therefore:

The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.

Answer:

Because of the presence of air resistance

Explanation:

When an object is in free fall, ideally there is only one force acting on it:

- The force of gravity, W = mg, that pushes the object downward (m= mass of the object, g = acceleration of gravity)

However, this is true only in absence of air (so, in a vacuum). When air is present, it exerts a frictional force on the object (called air resistance) with upward direction (opposite to the motion of free fall) and whose magnitude is proportional to the speed of the object.

Therefore, it turns out that as the object falls, its speed increases, and therefore the air resistance acting against it increases too; as a result, the at some point the air resistance becomes equal (in magnitude) to the force of gravity: when this happens, the net acceleration of the object becomes zero, and so the speed of the object does not increase anymore. This speed reached by the object is called terminal velocity.

Answer: Gravity does not act on objects near Earth’s surface.

Explanation:

When two satellites collide elastically, the total momentum before the collision is equal to the total momentum after the collision. However, the final velocities and the change in kinetic energy cannot be determined without additional information.

When two satellites collide elastically, the total momentum before the collision is equal to the total momentum after the collision. We can start by calculating the initial momentum:

Initial momentum = mass of the first satellite × velocity of the first satellite + mass of the second satellite × velocity of the second satellite

Plugging in the values:

Initial momentum = (2.50 × 10³ kg)(0.150 m/s) + (7.50 × 10³ kg)(0)

Since the second satellite is initially at rest (velocity = 0), the initial momentum simplifies to:

Initial momentum = (2.50 × 10^3 kg)(0.150 m/s) = 375 kg·m/s

Since momentum is conserved, the total momentum after the collision is also 375 kg·m/s. Let's assume the final velocities of the satellites are v1 and v2:

Final momentum = (2.50 × 10³ kg)(v1) + (7.50 × 10³ kg)(v2)

Setting the initial and final momenta equal to each other:

Initial momentum = Final momentum

375 kg·m/s = (2.50 × 10³ kg)(v1) + (7.50 × 10³ kg)(v2)

We can't solve for the individual velocities with only this equation, but we can use the fact that the satellites collide elastically. In an elastic collision, the total kinetic energy before the collision is equal to the total kinetic energy after the collision.

Using the formula for kinetic energy:

Kinetic energy = 1/2 × mass × velocity²

The initial kinetic energy is:

Initial kinetic energy = (1/2)(2.50 × 10³ kg)(0.150 m/s)² + (1/2)(7.50 × 10³ kg)(0)²

Simplifying:

Initial kinetic energy = (1/2)(2.50 × 10³ kg)(0.150 m/s)² = 56.25 J

The final kinetic energy is:

Final kinetic energy = (1/2)(2.50 × 10³ kg)(v1)² + (1/2)(7.50 × 10³ kg)(v2)²

Setting the initial and final kinetic energies equal to each other:

Initial kinetic energy = Final kinetic energy

56.25 J = (1/2)(2.50 × 10³ kg)(v1)² + (1/2)(7.50 × 10³ kg)(v2)²

Unfortunately, this equation cannot be solved with the given information and assumptions. We would need additional information, such as the angle of collision, to solve for the individual velocities and kinetic energies.

Answer:

84.6 J

Explanation:

The work done by the force is given by

[tex]W=Fd cos \theta[/tex]

where

W is the work done

F = 15 N is the force applied

d = 6.0 m is the displacement

[tex]\theta=20^{\circ}[/tex] is the angle between the force's direction and the displacement

Substituting the numbers into the equation, we find

[tex]W=(15 N)(6.0 m)cos 20^{\circ} =84.6 J[/tex]

A 5.0 kg object is pulled by a 15-N force acting 20 °C above the horizontal. After moving for 6.0 m, the work done is 85 J.

In physics, work is the energy transferred to or from an object via the application of force along a displacement.

A 5.0 kg object is pulled by a 15-N force acting 20 ° above the horizontal. We can calculate the work done after the object moved 6.0 m using the following expression.

W = F × s × cosθ

W = 15 N × 6.0 m × cos 20° = 85 J

where,

A 5.0 kg object is pulled by a 15-N force acting 20 °C above the horizontal. After moving for 6.0 m, the work done is 85 J.

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The buoyant force on a submerged object is the weight of the water it displaces ... the water it pushes out of the way.  That amount is simply the volume of the submerged object.  So the more volume is submerged, the greater will be the buoyant force acting on it.

Since Aluminum is less-dense than lead, the same 10kg of Aluminum needs a bigger container to hold it than 10kg of lead needs.  The aluminum needs  more volume to hold the same mass.

The aluminum displaces more water.  So the buoyant force acting on the aluminum is greater than the buoyant force acting on the lead. (B) .

I'm guessing this is a big part of the reason why fishing sinkers are not made of aluminum.

Aluminum has greater buoyant force than lead.

To determine the answer, we need to know about the buoyant force.

Thus, we can conclude that aluminum has greater buoyant force than lead.

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Explanation:

Given:

Va = 36 km/s = 3.6×10⁴ m/s

Vb = 12 km/s = 1.2×10⁴ m/s

T = 137 d = 1.18×10⁷ s

For each star, circumference = velocity * time:

2π R = V T

R = V T / (2π)

So Ra = Va T / (2π), and Rb = Vb T / (2π).

Sum of the forces on Alpha:

Ma Va² / Ra = G Ma Mb / (Ra + Rb)²

Va² / Ra = G Mb / (Ra + Rb)²

Mb = Va² (Ra + Rb)² / (G Ra)

Similarly, sum of the forces on Beta:

Mb Vb² / Rb = G Ma Mb / (Ra + Rb)²

Vb² / Rb = G Ma / (Ra + Rb)²

Ma = Vb² (Ra + Rb)² / (G Rb)

First, calculate Ra and Rb:

Ra = (3.6×10⁴) (1.18×10⁷) / (2π)

Ra = 6.78×10¹⁰

Rb = (1.2×10⁴) (1.18×10⁷) / (2π)

Rb = 2.26×10¹⁰

Therefore, the mass of Alpha is:

Ma = (1.2×10⁴)² (6.78×10¹⁰ + 2.26×10¹⁰)² / (6.67×10⁻¹¹ × 2.26×10¹⁰)

Ma = 7.81×10²⁹ kg

And the mass of Beta is:

Mb = (3.6×10⁴)² (6.78×10¹⁰ + 2.26×10¹⁰)² / (6.67×10⁻¹¹ × 6.78×10¹⁰)

Mb = 2.34×10³⁰ kg

chemical energy converts  into light, heat and sound  energy

Answer: Rapid Oxidation

Explanation:

In fireworks, the energy source is the rapid oxidation (burning or exploding) of gunpowder and other flammable chemicals. This burning causes the formation of gases that are heated and expand.

This rapid expansion involves three forms of energy : 1) The motive force to carry aerial fireworks into the sky, and to separate parts of them, 2) The heated molecules that give off radiance (visible light) in various forms of displays, and 3) The energetic vibration of air molecules that creates the sound of explosions.

Answer:

D. 2.8 × 10⁹ N

Explanation:

The force between two charges is directly proportional to the amount of charges at the two points and inversely proportional to the square of distance between the two points.

Fe= k Q₁Q₂/r²

Q₁= -0.0045 C

Q₂= -0.0025 C

r= 0.0060 m

k= 9.00 × 10 ⁹ Nm²/C²

Fe= (9.00 × 10 ⁹ Nm²/C²×-0.0045 C×-0.0025 C)/0.0060²

=2.8 × 10⁹ N

Answer:

D. 2.8 x 10^9 N

Explanation:

A P E X

λ = 2 m.

The easiest way to solve this problem is using the equation of frecuency of a wave f = v/λ, where v is the velocity of the wave, and λ is the wavelength.

To calculate the wavelength of a microwave light travels through a liquid, it moves at a speed of 2.2 x 10⁸ m/s. If the frecuency of the light wave is 1.1 x 10⁸ Hz, we have to clear λ from the equation f = v/λ:

f = v/λ -------> λ = v/f

λ = 2.2 x 10⁸ m/s / 1.1 x 10⁸ Hz

λ = 2 m (wavelength of the microwave)

7.5 x 10⁻¹¹m. An electromagnetic wave of frecuency 4.0 x 10¹⁸Hz has a wavelength of 7.5 x 10⁻¹¹m.

Wavelength is the distance traveled by a periodic disturbance that propagates through a medium in a certain time interval. The wavelength, also known as the space period, is the inverse of the frequency. The wavelength is usually represented by the Greek letter λ.

λ = v/f. Where v is the speed of propagation of the wave, and "f" is the frequency.

An electromagnetic wave has a frecuency of 4.0 x 10 ¹⁸Hz and the speed of light is 3.0 x 10⁸ m/s. So:

λ = (3.0 x 10⁸ m/s)/(4.0 x 10¹⁸ Hz)

λ = 7.5 x 10⁻¹¹m

Answer: [tex]1.212(10)^{-10} m[/tex]

Explanation:

The de Broglie wavelength [tex]\lambda[/tex] is given by the following formula:

[tex]\lambda=\frac{h}{p}[/tex] (1)

Where:

[tex]h=6.626(10)^{-34}\frac{m^{2}kg}{s}[/tex] is the Planck constant

[tex]p[/tex] is the momentum of the atom, which is given by:

[tex]p=m_{e}v[/tex] (2)

Where:

[tex]m_{e}=9.11(10)^{-28}g=9.11(10)^{-31}kg[/tex] is the mass of the electron

[tex]v=6(10)^{6}m/s[/tex] is the velocity of the electron

This means equation (2) can be written as:

[tex]p=(9.11(10)^{-31}kg)(6(10)^{6}m/s)[/tex] (3)

Substituting (3) in (1):

[tex]\lambda=\frac{6.626(10)^{-34}\frac{m^{2}kg}{s}}{(9.11(10)^{-31}kg)(6(10)^{6}m/s)}[/tex] (4)

Now, we only have to find [tex]\lambda[/tex]:

[tex]\lambda=1.2122(10)^{-10} m[/tex]>>> This is the de Broglie wavelength of the electron

Final answer:

Using the de Broglie equation, the de Broglie wavelength of an electron with a velocity of 6.00 × 106 m/s is calculated to be approximately 1.21 × 10-10 meters.

Explanation:

The de Broglie wavelength of an electron can be calculated using the de Broglie equation λ = h / (mv), where λ is the wavelength, h is Planck's constant (6.626 × 10-34 m2kg/s), m is the mass of the electron, and v is the velocity of the electron. The mass of an electron given is 9.11 × 10-28 g, which first needs to be converted to kilograms (kg) by dividing by 1000 to give 9.11 × 10-31 kg. Plugging the values into the equation: λ = 6.626 × 10-34 m2kg/s / (9.11 × 10-31 kg × 6.00 × 106 m/s), we can calculate the de Broglie wavelength to be approximately 1.21 × 10-10 meters, or 0.121 nanometers.

Ok so we are given the radius of 7cm and time of 5 seconds.

From the data we got we can calculate speed, frequency, perimeter and area of the semicircle.

Let's start with perimeter.

We know that perimeter of circle is [tex]2\pi r[/tex] so the perimeter of semicircle is [tex]\dfrac{2\pi r}{2}[/tex] or simply [tex]\pi r[/tex]

So the perimeter is equal to:

[tex]\pi r=\pi\cdot7\approx\boxed{22cm}[/tex]

So this is the length of a curve or let's say the distance.

Now let's look at the linear speed [tex]s=\dfrac{d}{t}[/tex] where d is distance and t time.

We know the distance and we know the time.

So let's calculate it.

[tex]s=\dfrac{d}{t}=\dfrac{22}{5}=\boxed{4.4\dfrac{cm}{s}}[/tex]

Hope this helps.

r3t40

Answer:

False

Explanation:

The inner planets are called terrestrial planets due to the surfaces are solid (similar to Earth)-made up of heavy metals, either have no moons or few moons.

The outer planets are called Jovian planets or gas giants because they are encased in gas.  They all have rings with plenty of moons.

The statement "The outer planets are similar to the planet Earth; they just happen to be farther away from the Sun." is False.

Therefore, the outer planets are not similar to the Earth, so the statement is false.

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Answer:

Zero Newtons

Explanation:

Newton's second law of motion states that the net force applied to an object is equal to the product between the object's mass and its acceleration:

[tex]F=ma[/tex]

In this case, we want the hockey puck to slide at constant velocity - constant velocity means zero acceleration:

a = 0

And so this means also that the net force is zero:

F = 0

However, the problem says that ice friction and air resistance are negligible - so there are no forces acting on the hockey puck. This means that the puck will continue its motion at constant velocity if we don't apply any other force on it.

Final answer:

Zero newtons. option D

Explanation:

The question pertains to the concept of Newton's first law of motion, which states that an object in motion will remain in motion with a constant velocity, and an object at rest will remain at rest, unless acted upon by a net external force.

In the scenario where a hockey puck is set in motion across a frictionless surface such as a frozen pond, and where air friction is also neglected, the force required to keep the puck sliding at constant velocity is zero newtons.

This is because once the puck is in motion, no additional force is needed to maintain its state of motion. In reality, ice isn't perfectly frictionless and air resistance is usually present, causing the puck to eventually slow down.

However, in the theoretical scenario presented, with no force opposing the puck's motion, no additional force is required to maintain its constant velocity, according to Newton's first law of motion.

Explanation:

There are three ways in which heat is transmitted:  

1. By Conduction, when the transmission is by the direct contact.  

2. By Convection, heat transfer in fluids (like water or the air, for example).  

3. By Radiation, by the electromagnetic waves (they can travel through any medium and in vacumm).

So, the space between the Earth and the Sun is vacuum, this means the energy cannot be transmitted by convection, nor conduction. It must be transmitted by electromagnetic waves that are able to travel with or without a medium, and this is called radiation.

Answer:

0.2 Hz

Explanation:

The frequency of a wave is given by

[tex]f=\frac{v}{\lambda}[/tex]

where

f is the frequency

v is the speed of the wave

[tex]\lambda[/tex] is the wavelength

For the ocean waves in this problem,

[tex]\lambda=15 m[/tex] is the wavelength

v = 3 m/s is the speed

So their frequency is

[tex]f=\frac{3 m/s}{15 m}=0.2 Hz[/tex]

The frequency of ocean waves passing under an anchored boat can be calculated using the wave equation v = f λ. In this case, the velocity of the waves is given as 3 meters per second and the distance between wave crests (wavelength) is given as 15 meters. The frequency at which these ocean waves pass under an anchored boat is 0.2 Hz.

The frequency of ocean waves passing under an anchored boat can be calculated using the wave equation v = f λ, where v is the velocity of the waves, f is the frequency, and λ is the wavelength.

In this case, the velocity of the waves is given as 3 meters per second and the distance between wave crests (wavelength) is given as 15 meters. We need to find the frequency.

Using the wave equation, we can rearrange it to solve for frequency as f = v / λ. Substituting the given values, we get f = 3 m/s / 15 m = 0.2 Hz.

Therefore, the frequency at which these ocean waves pass under an anchored boat is 0.2 Hz.

The atomic nuclei of almost all elements consist of protons and neutrons.

The nucleus of an atom has very small dimensions. However, it occupies its central part and concentrates more than 99% of its total mass.

It is in the nucleus that the protons (positive charge) and neutrons (neutral charge) are found.

Ok so we know that electric power is:

[tex]P=UI=I^2R[/tex]

If we express resistance.

[tex]R=\dfrac{P}{I^2}[/tex]

Now if you have 100W of power you will probably get a bigger resistance than with 40W of power.

However here it says that the resistance of 40W bulb is bigger than 100W bulb. Which means the statement is incorrect.

Hope this helps.

r3t40

Answer:

Line 3 has a mistake.

Explanation:

Electromagnetic waves consist of oscillations of electric and magnetic fields that oscillate perpendicular to the each other. Therefore, Line 1 is correct.

Also, the fields in an electromagnetic waves oscillate perpendicular to the direction of propagation of the wave: therefore, they are transverse waves. So Line 2 is also correct.

Electromagnetic waves, contrary to mechanical waves, do not need a medium to propagate: so, they can also travel through a vacuum. Therefore, Line 3 is wrong.

Finally, all electromagnetic waves travel through a vacuum at the same speed, called speed of light:

[tex]c=3\cdot 10^8 m/s[/tex]

So, Line 4 is also correct.

Answer:

Line 3 is the mistake

Explanation:

Line 3 is incorrect because electromagnetic waves can travel with or without a medium, meaning they CAN travel through space.

Answer:

He is known as the first microbiologist and also “the Father of Microbiology” because he was the first to observe bacteria underneath a microscope. He made many other significant discoveries in the field of biology and also made important changes to the microscope.

Explanation:

hope this helps. and if it did pls mark brainliest :)

Answer: When a lightning bolt travels from the cloud to the ground it actually opens up a little hole in the air, called a channel. Once then light is gone the air collapses back in and creates a sound wave that we hear as thunder. The reason we see lightning before we hear thunder is because light travels faster than sound!

Explanation:

Answer:

Light waves travel faster than sound waves

Explanation:

Answer: its c

Explanation:

Total energy is conserved.

Energy = potential energy + kinetic energy as other forms of energy are neglected.

Clearly , position A is at a higher position from the ground , so it has more potential energy.

As the energy is conserved , the kinetic energy at A must have decreased making the total energy the same as that during B.

So,to sum it up  

potential energy of the student increases and the kinetic energy decreases as he moves from B to A

When the swing goes from Position B to Position A, potential energy increases due to height gain, while kinetic energy decreases as the swing slows down.

When a swing moves from Position B (the lowest point) to Position A (a higher point), the potential energy of the student increases while the kinetic energy decreases. This is because as the swing rises, it slows down due to gravity working against the motion, converting kinetic energy into potential energy. At the highest point of the swing (Position A), the swing has its maximum potential energy and minimum kinetic energy. Conversely, as the swing descends back toward Position B, the potential energy is converted back into kinetic energy, increasing the speed of the swing.

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Answer:

object moves up

Explanation:

Answer:

The object F moves up

Explanation:

Explanation:

A force that leads to movement of an object is known as work.

The energy present in an object due to its position in a gravitational field is known as gravitational potential energy.

Kinetic energy is the energy obtained by an object due to its motion.

For example, when Jerome is swinging on a rope then there occurs movement in the swing due to which the swing has kinetic energy.

Since, a force has been applied on the swing to make it move. Hence, a work is also done.

Therefore, we can conclude that if Jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, work is being done.

Answer:

the answer is B ( work )

Explanation:

A.) compression

B.) work

C.) radiation

D.) energy creation

Answer:

I believe the answere is B)

Explanation:

Well, as the light enters the atmosphere it meets resestance.And since the atmosphere is essentially a thick layer of chemicals in the form of gasses under pressure it isn't very smooth.So as a result, the light mainly scatters towards different dirrections.I am happy to help.Contact me if you have any further questions.

Yours sincerely,

Manos.

Answer:

The correct answer is C.

Explanation:

Answer:

It's C

Explanation:

Δλ =  3.103 m.

To solve this problem we have to know the speed of sound in both elements water and ice.

Element            Speed of sound

Water (25°C)           1493 m/s

Ice                           3200 m/s

The velocity of a wave is given by the equation v = λf, where λ is the wavelength, and f is the frecuency of the wave.

In order to calculate the wavelength we have to clear λ in the equation v = λf, resulting:

λ = v/f

Calculating the wavelength in both elements:

λ(water) = 1493 m/s / 550 Hz = 2.715 m

λ(ice) = 3200 m/s / 550 Hz = 5.818 m

So, the difference in wavelength between the wave produced in ice and the wave produced in water is:

Δλ = λ(water) - λ(ice) = 5.818 m - 2.715 m

Δλ =  3.103 m

Answer:

3.1 m

Explanation: