You throw a small rock straight up from the edge of a highway bridge that crosses a river. The rock passes you on its way down, 8.00 s after it was thrown. What is the speed of the rock just before it reaches the water 25.0 m below the point where the rock left your hand?

Answer:

D. Reaches a maximum height of 439.20 meters in 9.2 seconds.

Explanation:

Given

h = –5t²+ 92t + 16

then

h' = 0  when the boulder reaches its maximum height

(–5t²+ 92t + 16)' = - 10t + 92 = 0

⇒ t = 92/10

⇒ t = 9.2 s

the maximum height will be

h = –5(9.2)²+ 92(9.2) + 16

h = 439.20 m

Answer: 2.55meter

Explanation: Using the second equation of motion.

S{hieght} = U*t + {g*t²}/2

Where U is initial velocity =0m/s

g is acceleration due to gravity 10m/s²

t is time 1secs

So we have,

hieght = 0 + {g*t²}/2

hieght = {10*(1)²}/2

Total hieght travelled is 10/2

Which is 5 meter.

But we are asked to find the hieght above the window which as a hieght of 2.45meter.

So,

hieght above window would be

{5 - 2.45}meter

Which is 2.55 meter.

Answer:

a. theory

Explanation:

A scientific theory is a set of facts and rules, that is, scientific laws, which express relationships between observations of these facts. Therefore it is a set of principles to explain a certain type of natural phenomena. Thus, the strength of a scientific theory is related to the diversity of phenomena it can explain and its simplicity.

Final answer:

A set of facts and relationships that can explain and predict phenomena is known as a theory, which is a well-supported scientific explanation and the foundation of scientific knowledge.

Explanation:

A set of facts and relationships between facts that can explain and predict related phenomena is called a theory. A theory is a well-supported explanation of observations and is often used as the foundation of scientific knowledge. It goes beyond a hypothesis, which is a tentative explanation that can be tested, by being supported by a substantial amount of empirical evidence and experimentation. In contrast to a theory, a law summarizes the relationships between variables without explaining why they occur.

The process of discovery in science usually follows the scientific method, where hypotheses are made and then tested through experiments and observation to acquire new knowledge.

Answer: [tex]12 mi[/tex]

Explanation:

Velocity [tex]V[/tex] is mathematically defined as:

[tex]V=\frac{d}{t}[/tex] (1)

Where:

[tex]V=3 \frac{mi}{h}[/tex] is Gina's velocity

[tex]t=4 h[/tex] is the time Gina spends walking

[tex]d[/tex] is the distance Gina has walked

Isolating [tex]d[/tex] from (1):

[tex]d=Vt[/tex] (2)

[tex]d=(3 \frac{mi}{h})(4 h)[/tex] (3)

Finally:

[tex]d=12 mi[/tex] This is the distance Gina has walked

Answer:

Sound waves and fetal imaging is related to the ultrasound.

Electromagnetic wave and soft tissue imaging is related to the MRI.

Explanation:

Ultrasound scans is basically a process in which high frequency sound waves are used for the fetal imaging or examining the internal organs like liver, kidneys etc. It's the safe procedure as no radiations are involved in this case.

However the MRI stands for Magnetic resonance imaging that use the electromagnetic waves and is best for the soft tissue imaging etc.

Sound waves and electromagnetic waves are key to ultrasound and MRI imaging. Ultrasound uses sound waves for applications like fetal imaging, while MRI uses electromagnetic waves for soft-tissue imaging.

To match the characteristic or descriptive phrase to the type of application it describes:

Ultrasound is a medical imaging technique that uses high-frequency sound waves to create images of the inside of the body. It is particularly useful for fetal imaging during pregnancy as it is non-invasive and safe for both the mother and fetus. On the other hand, Magnetic Resonance Imaging (MRI) uses electromagnetic waves in the radio-frequency range to create detailed images of the body's soft tissues, making it invaluable for detecting conditions within the body's interior.

Answer:

False: Quaternary structure is achieved when multiple polypeptide chains in protein come together.

Explanation:

There are four levels of protein structure: primary, secondary, tertiary, and Quaternary structure.

Tertiary structure is a protein structure, which is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids.

However, Quaternary structure is achieved when multiple polypeptide chains in protein come together.

problem is worked out down below in an attachment

Final answer:

It takes approximately 0.015 seconds for a nerve impulse from a stubbed toe to reach the brain, calculated based on the speed of the nerve impulse (100 m/s) and the estimated distance (1.5 meters).

Explanation:

To calculate the time it takes for a nerve impulse to travel from a stubbed toe to the brain, we need to consider the speed of the nerve impulse and the distance it must travel. The speed of a nerve impulse is about 100 m/s. Assuming an average distance from the toe to the brain via the spinal cord is approximately 1.5 meters (taking into account the height of an individual and that nerve paths are not completely straight), we can use the formula:

Time = Distance / Speed

Plugging in the values gives us:

Time = 1.5 m / 100 m/s = 0.015 seconds.

So, it takes approximately 0.015 seconds for a nerve impulse from a stubbed toe to reach the brain. This rapid transmission allows the body to respond quickly to stimuli, protecting it from further injury.

Answer:

Explanation:

mass of electron = 1.9 ×[tex]10^{-31} kg[/tex]

mass of proton = 1.67 ×[tex]10^{-27}[/tex][tex]kg[/tex]

Gravitational Force = [tex]F_{g}[/tex] = [tex]\frac{Gm_{p}m_{e} }{r^{2} }[/tex] = [tex]\frac{6.67 * 9.1* 1.67*10^{-69} }{r^{2} }[/tex]

Electrostatic Force = [tex]F_{E}[/tex] = [tex]\frac{1}{4\pi epsilon} \frac{e^{2} }{r^{2} }[/tex] = [tex]\frac{9*10^{9}* 1.6*1.6* }{r^{2} }[/tex]×[tex]10^{-38}[/tex]

[tex]\frac{F_{g} }{F_{E} }[/tex] = [tex]4.47[/tex]×[tex]10^{-40}[/tex]

Answer:

Because electromagnetic waves can travel through empty space

Explanation:

The energy that is emitted from the sun is transferred to the earth in the form of radioactive waves. These waves are originated due to the vibration between the electric and magnetic fields. As this energy reaches the earth, it warms the earth's atmosphere, resulting in the transfer of heat energy in three possible ways namely the conduction, convection, and radiation.

This electromagnetic waves do not require any matter for the transmission of energy, and can easily travel in empty space from the core of the sun to the earth and other nearby planets. Whereas other types of waves cannot travel in space, so it is transferred in the form of electromagnetic waves only.

Answer:

The electromagnetic waves can pass through empty space.

Explanation:

Answer:

EPAct of 1992.

Explanation:

The Energy Policy Act (EPAct) is a United States Of America government act passed in the year 1992 and became effective in October 24, 1992.

The Energy Policy Act was established to address the energy needs in the United States of America by amending laws to increase and provide incentives for clean and renewable energy and also to decrease the dependence on imported energy.

Answer:

a. [tex]Change in  Voltage=12*10^{4}V[/tex]

b. [tex]Change in  Voltage=12*10^{4}V[/tex]

Explanation:

The work done in moving an electric charge round a circuit is express as

[tex]workdone=voltage*charge \\Wd=v*q[/tex]

The voltage is in-turn define as the electric potential energy per unit charge.

[tex]Voltage=\frac{potitntial energy }{charge}\\[/tex]

a. for a 12J work done  on a charge of value 0.0001C, we can compute the voltage change as

[tex]Voltage=\frac{potitntial energy }{charge}\\Voltage=\frac{12J}{0.0001C}\\ Voltage=12,0000J/C\\ Change in Voltage=12*10^{4}V[/tex]

a. for a 24J work done  on a charge of value 0.0002C, we can compute the voltage change as

[tex]Voltage=\frac{potitntial energy }{charge}\\Voltage=\frac{24J}{0.0002C}\\ Voltage=12,0000J/C\\Change in Voltage=12*10^{4}V[/tex]

The voltage change in (a) is 1.2 × 10⁵ J/C and in (b) is 1.2 × 10⁵ J/C.

a) Based on the given information,

• Work done (W) is 12 J and charge (q) is 0.0001 C.

The change in voltage is determined by using the formula,

= W/q

Now putting the values we get,

= [tex]\frac{12}{0.0001} J/C[/tex] or 1.2 × 10⁵J/C

b) Based on the given information,

• Work done (W) is 24J and charge (q) is 0.0002 C.

The change in voltage can be calculated as,

= W/q

Putting the values we get,

=[tex]\frac{24}{0.0002} J/C[/tex] or 1.2 × 10⁵J/C

Thus, the voltage change in both the conditions is 1.2  × 10⁵J/C.

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The average force between the ball and the bat during the contact is 1,566 N.

The given parameters;

The average force between the ball and the bat during the contact is determined by applying Newton's second law of motion.

F = ma

where;

The average force is calculated as follows;

[tex]F = ma = m\frac{v}{t} \\\\F = \frac{mv}{t} \\\\F = \frac{0.145 \times 27}{2.5 \times 10^{-3}} \\\\F = 1,566 \ N[/tex]

Thus, the average force between the ball and the bat during the contact is 1,566 N.

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To calculate the average force between the ball and bat during contact, you first calculate the speed the ball leaves the bat using the gravitational potential energy formula. Find the change in velocity, then use the formula for force using this change in velocity and the given time.

The subject of this question is physics, specifically involving the concepts of force, mass, speed, and time. This problem first requires using the equation for gravitational potential energy to find the speed at which the ball leaves the bat. That is Potential energy = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height. This will give you the final speed of the baseball after the contact with the bat.

Next, find the change in velocity (or 'delta v') by subtracting the initial speed of the baseball from its final speed. The average force can then be calculated using Newton's second law transformed in impulse form: Force = delta p / delta t = m * delta v / delta t, where delta p is the change in momentum, delta v is the change in speed, and delta t is the change in time.

This calculation should provide the answer to your question, and requires understanding of physics concepts such as gravitational potential energy, impulse, and force.

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Answer: a. 85km/hr b.82.3km/hr

c. 84km/hr

Explanation: first let take the total time from San Antonio to Houston to be 2hr.

Half time 1hr was covered with speed of 72km/hr

Distance = speed*time=72km/hr *1hr

=72km

So too with the second half of 1hr covered with speed of 98km/hr

Distance = 98km

Total distance from Houston to San Antonio is 98+72 =170km

a. Average speed from San Antonio to Houston is

S1 =170/2

=85km/hr

b.half distance from Houston to San Antonio which is 170km/2

= 85km was covered with speed of 72km/hr first half, so time

t = dist/speed

t = 85/72 = 1hr 12 mins

Remaining 85 km covered with a speed of 98km/hr

Time = 85/98 = 0.88*60min

= 52 mins

Total time = 1hr +12mins +52mins

=2hr4mins= 124/60 hr

So average speed = distance/time

=170/124/60

Using reciprocal law

Average speed S2= 170*60/124

= 82.3km/hr

C. Average speed to and fro(entire tripe)

= (85+82.3)/2

=84km/hr

Answer:

Food record

Explanation:

A food record method is an assessment, study or act of collecting data related to food.

Although Food record method is time consuming and may not be accurate if subjects modify their eating habits during the time of the study the data collected here are of great importance. Some of the importance are;

(1). It helps in the registration of foods.

(2). The data can be used to describe a population's intake.

(3). The data can be used as a reference parameter in validation studies.

(4). The data can also be used with the Food Frequency Questionnaire.

It other disadvantage apart from its time consuming and error that might occur during the process of conducting the research is that it might be burdensome to the respondents.

Answer:

[tex]t_h=8.75\ s[/tex]

Explanation:

For a projectile the total time it stays in the air is called the flight time. The path traced during a projectile motion is parabolic with symmetry of time and distance.

Given that the projectile having a flight time of 17.5 seconds, will reach the top point in half of the flight time taken by it:

So, [tex]t_h=\frac{T}{2}[/tex]

[tex]t_h=\frac{17.5}{2}[/tex]

[tex]t_h=8.75\ s[/tex] is the time by the end of which the projectile will be at its apex having the vertical component of velocity as zero.

Do note that during a projectile analysis we neglect the air resistance due to which we have a constant horizontal component of the velocity and the vertical component of the velocity varies under the influence of gravity. The vertical velocity at the top becomes zero.

Answer:

at zero point : GPE = 0 J

at max height : GPE = 633.7 J

Explanation:

the gravitational potential energy at the lowest point is zero

maximum height relative to the lowest point = h =1.70 m

G potential energy at max height = mgh = (38kg)(9.81m/s^2)(1.7)

                                           = 633.7 J

There are mistakes in the question as the unit of speed and height is not mention here.The correct question is here

A student standing on the ground throws a ball straight up. The ball leaves the student's hand with a speed of 16.0m/s when the hand is 1.80m above the ground.How long is the ball in the air before it hits the ground? (The student moves her hand out of the way.)

Answer:

t=3.37s

Explanation:

Given Data

As we have taken hand at origin and positive upward

So given data are

[tex]y_{i}=0m\\y_{f}=-1.80m\\v_{i}=16.0m/s\\a=g=9.8m/s^{2}[/tex]

To find

time taken by the ball before it hits the ground

Solution

By using the common kinematic equation

[tex]y_{f}=y_{i}+v_{i}t+0.5at^{2}[/tex]

Put the given values and find for t

So

[tex]-1.80=0+16.0t+(0.5*(-9.8)t^{2} )\\-1.80=16.0t-4.9t^{2}\\ 4.9t^{2}-16.0t-1.80=0[/tex]

Apply quadratic formula to solve for t

[tex]t=\frac{-(-16.0)+\sqrt{(-16)^{2}+4(4.9)(-1.80)} }{2(4.9)}\\ t=3.37s[/tex]

Answer:

a. 34.6 Nm

b.24.4 Nm

Explanation:

a.

78 cm = 0.78 m

W = F =mg

m1 = mass of steel ball = 3 kg

m2 = mass of long arm = 3.8 kg

moment due to steel ball = Fd =(m1*g)*(0.78)= (3*9.81)(0.78)=22.95 = 23 Nm

moment due to arm =Fd=(m2*g)*(0.78*0.4)= (3.8*9.81)(0.312)=11.63 = 11.6 Nm

net moment = 23 +11.6 = 34.6 Nm

b. now in this the angle will change the perpendicular moment arm

   moment due to steel ball = (3*9.81)*(0.78cos45) = 16.23 =16.2 Nm

   moment due to arm = (3.8*9.81)(0.4*0.78cos45) = 8.22 = 8.2 Nm

net moment = 16.2 +8.2 = 24.4Nm

(a) The magnitude of the torque about his shoulder due to the ball and the weight of his arm parallel to the floor is 34.55 Nm.

(b) The magnitude of the torque about his shoulder due to the ball and the weight of his arm straight, but 45° below horizontal is 24.43 Nm.

The given parameters;

A sketch of the position of the ball and the arm;

---------------------------------------------------------------------------78cm

↓           40%               ↓        

3 kg                            3.8 kg        

Take moment about the arm;

The moment due to arm (clockwise), is calculated as follows;

M₁  = Fd = (3.8 x 9.8) x (0.4 x 0.78) = 11.62 Nm

The moment due to ball (clockwise), is calculated as follows;

M₂ = Fd = (3 x 9.8) x (1 x 0.78) = 22.93 Nm

The magnitude of the torque about his shoulder due to the ball and the weight of his arm parallel to the floor is calculated as;

τ = M₁ + M₂

τ =  11.62 + 22.93 = 34.55 Nm  

(b) The moment at angle 45⁰ below the horizontal is calculated as follows;

The moment due to arm (clockwise), is calculated as follows;

M₁  = Fd = (3.8 x 9.8) x (0.4 x 0.78) x (cos45) = 8.22 Nm  

The moment due to ball (clockwise), is calculated as follows;

M₂ = Fd = (3 x 9.8) x (1 x 0.78) x cos(45) = 16.21 Nm

The magnitude of the torque about his shoulder due to the ball and the weight of his arm straight, but 45° below horizontal is calculated as;

τ = M₁ + M₂

τ = 8.22 + 16.21

τ = 24.43 Nm.

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Explanation:

We have equation of motion v² = u² + 2as

Initial velocity, u = 300 m/s  

Acceleration, a = ?

Final velocity, v = 400 m/s  

Displacement,s = 4 km = 4000 m

Substituting  

v² = u² + 2as

400² = 300² + 2 x a x 4000

a = 8.75 m/s² = 8.8 m/s²

The acceleration is 8.8 m/s²

The answer got is reasonable.

Final answer:

The jet's acceleration, assuming it to be a constant acceleration, is 8.75 m/s². The initial calculation of 8.8 m/s² was close, but using the kinematic equation we find the precise acceleration value.

Explanation:

Let's calculate the jet's acceleration with the given information. We know the initial speed (u), the final speed (v), and the distance (s) covered during acceleration:

We can use the kinematic equation:

v² = u² + 2as

Where:

Plugging in the values:

4002 = 3002 + 2a(4000)

Solving for a gives:

a = (400² - 300²) / (2 × 4000)

a = (160000 - 90000) / 8000

a = 70000 / 8000

a = 8.75 m/s²

Your computation of 8.8 m/s² is quite close but let's ensure we're using the correct figures. The actual acceleration is 8.75 m/s² when calculated correctly, so a slight revision may be needed on your calculation depending on your rounding during the process.

Answer:

The change in kinetic energy is 5,909,400J and the terminal speed of the car is 160,800mph

Explanation:

Change in kinetic energy = mg(h2 - h1)

Mass (m) = 1500kg, g = 9.8m/s^2, final distance (h2) = 402m, initial distance (h1) = 0m

Change in kinetic energy = 1500×9.8×(402 - 0) = 1500×9.8×402 = 5,909,400J

From equations of motion

h = ut + 1/2gt^2 [u is initial speed and is equal to zero because the car drag racing began from a standing start (rest)]

h = 1/2gt^2

402 = 1/2 × 9.8t^2

402 = 4.9t^2

t^2 = 402/4.9 = 82.04

t = √82.04 = 9.06s × 1h/3600s = 0.0025h

Terminal speed = distance/time = 402m/0.0025h = 160,800mph

Answer:

Coefficient of friction will be 0.296

Explanation:

We have given initial speed of the stone u = 8 m /sec

It comes to rest so final speed v = 0 m /sec

Distance traveled before coming to rest s = 11 m

According to third equation of motion

[tex]v^2=u^2+2as[/tex]

So [tex]0^2=8^2+2\times a\times 11[/tex]

[tex]a=\frac{-64}{22}=-2.90m/sec^2[/tex]

Acceleration due to gravity [tex]g=9.8m/sec^2[/tex]

We know that acceleration is given by

[tex]a=\mu g[/tex]

So [tex]2.90=9.8\times \mu \\[/tex]

[tex]\mu =\frac{2.9}{9.8}=0.296[/tex]

So coefficient of friction will be 0.296

To calculate the coefficient of kinetic friction, we first use Newton's second law to calculate the force of friction. Then, we divide that force by the normal force, yielding our coefficient.

To find the coefficient of kinetic friction, you'll need to use the formula for kinetic friction (f = μkN), where 'f' is the force of friction, 'μk' is the coefficient of kinetic friction, and 'N' is the normal force. In this case, the force of friction can be found by using Newton's second law (f = ma), where 'm' is the mass of the stone and 'a' is its acceleration. The stone's acceleration can be found using the formula a = (vf - vi)/t, where 'vf' is the final velocity (0 m/s, since the stone comes to rest), 'vi' is the initial velocity (8.0 m/s), and 't' is the time it takes for the stone to stop. Once you've found the force of friction and the normal force (which is equal to the weight of the stone, or mg, where 'g' is the acceleration due to gravity), you can solve for the coefficient of kinetic friction.

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Answer:

2.24 T

Explanation:

From Electromagnetic Field,

F = BILsin∅................ Equation 1

Where F = Force on the wire, B = Field strength, I = current flowing in the conductor, L = length of the conductor, ∅ = The angle the conductor makes with the magnetic field.

Making B the subject of the equation,

B = F/ILsin∅..................... Equation 2

Given: F = 2.15 N, I = 32 A, L = 3.00 cm = 0.03 m, ∅ = 90° ( the wire is perpendicular to the magnetic field)

Substitute into equation 2

B = 2.15/(32×0.03×sin90°)

B = 2.15/0.96

B = 2.24 T.

Hence the Field strength = 2.24 T

Answer:

3.486 km

Explanation:

Suppose Joe and Max's directions are perfectly perpendicular (east vs north). We can calculate their distance at the destinations using Pythagorean theorem:

[tex]s = \sqrt{J^2 + M^2}[/tex]

where J = 0.5 km and M= 3.45 km are the distances between Joe and Max to their original parting point, respectively. s is the distance between them.

[tex]s = \sqrt{0.5^2 + 3.45^2} = \sqrt{12.1525} = 3.486 km [/tex]

Answer:

20 rad/s^{2}

Explanation:

weight / force (F) = 150 N

radius (r) = 0.5 m

mass (m) = 15 kg

angular acceleration = tangential acceleration / radius

where

angular acceleration =  10 / 0.5 = [tex]20 rad/s^{2}[/tex]

Answer:GiGi

Explanation:

Answer:

15.66 rad/s

Explanation:

The vertical motion and horizontal motion are independent of each other.

t = √ ( 2 s/ g) where t = time for the ball to reach the ground and s is the height of the cliff = 18.0 m

t = √ ( 36 / 9.81 ) = 1.916 secs

horizontal distance travel = ut where u is the horizontal velocity of the stone = 30 × r (radius)

tangential velocity V = angular velocity ( ω) × radius

distance traveled = ω × r × t = 30 × r

radius cancelled on both side

ω = 30 / 1.9156 = 15.66 rad/s

Answer:

The magnifying power of this telescope is (-60).

Explanation:

Given that,

The focal length of the objective lens of an astronomical telescope, [tex]f_o=30\ cm[/tex]

The focal length of the eyepiece lens of an astronomical telescope, [tex]f_e=5\ mm=0.5\ cm[/tex]

To find,

The magnifying power of this telescope.

Solution,

The ratio of focal length of the objective lens to the focal length of the eyepiece lens is called magnifying of the lens. It is given by :

[tex]m=\dfrac{-f_o}{f_e}[/tex]

[tex]m=\dfrac{-30}{0.5}[/tex]

m = -60

So, the magnifying power of this telescope is 60. Therefore, this is the required solution.

Answer: The speed is 0.4694 m/s.

Explanation:

S.I or M.K.S system has seven fundamental units which are used to find derived units

1) Mass - Kilogram

2) Length - meter

3) Time - Seconds

4) Electric Current - Ampere

5) Amount of substance - Moles

6) Intensity of light - Candela

7) Temperature - Kelvin

The conversion used from miles to feet is:

1 mile = 1609 m

1.000 miles= [tex]\frac{1690}{1}\times 1.000=1690m[/tex]

The conversion used from hour to sec is:

1 hr = 3600 sec

We are asked: 1.000 miles/hr = ? m/s

[tex]1.000miles/hr=\frac{1690}{3600}m/sec=0.4694m/sec[/tex]

Therefore, the speed in SI unit is 0.4694

Answer:

we are on the same frame of reference moving with the earth with the same velocity.

Explanation:

Answer:

time of fall and the final velocity

Explanation:

the mass of solid ball is more than the mass of hollow ball.

According to the third equation of motion

v² = u² + 2gh

As the final velocity v does not depend on the mass of the object, so the final velocity of both the ball is same.

According to the first equation of motion

v = u + gt

As v is same for both the balls, the time is also same for both the balls.

So, they both have same time of fall and final velocity.