Cummlative Physics Exam Review

In the equation for centripetal force, which expression represents the centripetal acceleration of the object?

(v^2)/r

A 60.0 kg object is moving east at 8.00 m/s, and then slows down to 4.00 m/s. How much work was done?

-1,440 J

The forces acting on a child sitting in a seat are described by the free-body diagram shown. What is the net force acting on the child? Fn= 100 Up Fg= -100 Down

0 N

How far from the center of the ride is the child?

0.36 m

A cyclist rides at a constant speed of 4.5 m/s around a curve. If the centripetal acceleration is 29 m/s2, what is the radius of the curve?

0.70 m

If 3,600 J of work is done in 3.0 s, what is the power?

1,200 W

The energy transfer diagram represents the energy of a person diving into a pool. How much thermal energy is generated?

1000 N

A box is pulled up a rough ramp that makes an angle of 22 degrees with the horizontal surface. The surface of the ramp is the x-plane. What is the magnitude of the force of tension if the net force in the x direction of 98 N?

139 N

An elevator has a weight of 14,700 N and has an acceleration of -0.30 m/s2. The free-body diagram shows the forces acting on the elevator. To the nearest whole number, what is the force of tension, Ft, acting on the elevator?

14,250 N

The table shows data for the planet Uranus. To the nearest whole number, how much would a 25.0 kg rock weigh on Uranus?

218 N

How much heat is needed to vaporize 10.00 grams of water at 100.0°C? The latent heat of vaporization of water is 2,259 J/g.

22,590 J

Object Z passes object Y after how many seconds?

3

A bicycle tire has a radius of 0.23 m. The tire spins at a constant speed with a centripetal acceleration of 42 m/s2. What is the tangential speed of the tire?

3.1 m/s

What is the tangential speed of the tire?

3.1 m/s

An object with a mass of 20 kg has a net force of 80 N acting on it. What is the acceleration of the object?

4 m/s^2

A moving company collects data about couches they move and displays the data in a table. The force along the ramp, the angle of the ramp, and the height the couch is raised to are shown. Which statements correctly compare the work done to move the couches? Check all that apply.

4. The work for couch 2 is less than the work for couch 3. 5. The work for couch 3 is greater than the work for couch 1. 6. The work for couch 2 is greater than the work for couch 1.

The orbital period of a satellite is 2 × 106 s and its total radius is 2.5 × 1012 m. The tangential speed of the satellite, written in standard notation, is ______.

7,850,000 m/s

If a 4.5 kg object is dropped from a height of 6.0 m, what will be its velocity when it is halfway toward the ground? (Use g = 9.80 m/s2, and ignore air resistance.)

7.7 m/s

How much total energy does this truck put out?

800 J

What is the magnitude of force that the ground exerted on the egg?

9.2 N

A heat engine has a temperature of 1800 K. Some of the heat from the engine flows to the surroundings, which are at a temperature of 160 K. What is the approximate efficiency of the engine?

91%

Which formula can be used to find the centripetal acceleration of an orbiting object?

Ac= (v^2)/r

The acceleration due to gravity on Mercury is 3.7 m/s2, which is about six times the acceleration due to gravity on Pluto.

An object weighs about one-sixth as much but has the same mass on Pluto as on Mercury.

Suppose the exhaust system on a heat engine is not functioning properly. Which statement best explains how this will affect the engine?

Burned gases will not be released into the surrounding air.

Which graph shows an object with constant acceleration?

C. Downward, Straight line with negative slope.

Which diagram best illustrates what happens when electromagnetic waves strike a reflective material?

D. Deflected ray

A push broom is being pushed down across a rough floor. The broom moves to the right.

D. Fn Up, Ff Left, Fp Downward Right in Quadrant 4, Fg Down

Which best describes how to correct Hannah's error?

Describe the calculation for speed as "dividing distance by time."

How would scientists most likely describe the system of the Earth in regard to energy?

Earth is an open system because heat energy from the Sun enters through the atmosphere.

Which is an action that can cause an object to move or change its state of motion?

Force

Which energy transformation occurs after a skydiver reaches terminal velocity?

Gravitational potential energy transforms into thermal energy.

Rahul wants to change the motion map shown so that it shows uniform circular motion. What change should Rahul make?

He should change the lengths of the vectors that point tangent to the circle so that each is the same length.

How does an airbag help protect a passenger in a car following a car accident?

It increases the passenger's stopping time, and this decreases the force.

What is the formula for calculating kinetic energy?

KE = (1/2)mv^2

Which is an example of radiation?

Melting Snowman

Allen made a diagram to compare radiation and conduction. Which label belongs in the area marked Y?

Must involve temperature differences between substances or objects

Which label belongs in the area marked Y?

Must involve temperature differences between substances or objects

Reference frame definitely changes when ______ also changes.

Position

Temperatures of four liquid substances are shown in the chart. Which statement is best supported by the data in the chart? W=40 X=37 Y=19 Z=37

Substance W will transfer thermal energy to substance X through conduction if they are mixed.

Which statement is best supported by the data in the chart?

Substance W will transfer thermal energy to substance X through conduction if they are mixed.

Substance X transfers thermal energy to substance Y through conduction. What is an accurate conclusion about the condition of both substances before conduction occurred?

Substance X's molecules were faster than substance Y's.

A boy is running to the east and jumps into a stationary boat in a lake. Once the boy lands in the boat, the boat moves to the east. Which best compares the initial momentum of the boy with the final momentum of the boy/boat system?

The initial momentum of the boy is equal to the boy/boat because the final velocity of the boat is less than the initial velocity of the boy.

Jerome places a bag of flour on a scale. The scale shows that the bag has a weight of 17 N. Which is the reaction force of the bag sitting on the scale?

The scale exerts a 17 N force up on the bag.

The pitcher on a softball team starts a windup to throw a pitch, as shown. He wants to throw the pitch level with the ground and in the direction he is facing. At which point should he release the pitch?

W

Which describes the movement of a fluid during convection?

Warm fluid rises and cool fluid sinks.

The diagram shows a heating curve for water. Which statement best describes what is happening at segment W-X?

Water is absorbing heat.

Which statement best describes what is happening at segment W-X?

Water is absorbing heat.

Why is it important to know the direction of the force applied to a moving object and the direction in which the object is moving when determining the work done on the object?

When there is an angle between the two directions, the cosine of the angle must be considered.

At which landing site would the lander have the greatest amount of gravitational potential energy?

X

Four landing sites are proposed for a lander. Data about the sites are listed in the table. At which landing site would the lander have the greatest amount of gravitational potential energy?

X

The chart shows data for an object moving at a constant acceleration. Which values best complete the chart? Time: 0,1,2,3. Velocity: 0,X,Y,Z.

X: 2 Y: 4 Z: 6

Allison drew a diagram to illustrate radiation. Allison drew a diagram to illustrate radiation.

X: Hot Y: Cold

An object is represented by the dot on the motion map. Which object is most likely represented by the dot?

a ball on a string that stopped at the top of a vertical loop

Four different balls are moving at the same velocity. Which will have the greatest kinetic energy as it rolls?

a bowling ball

Which is the correct order of materials in terms of reflectivity, from least to greatest?

black asphalt, brown soil, beige sand, white paper

The motion map shows an object's position and velocity at given times. How can the map be changed so it shows constant acceleration after the object changes direction?

by adding vectors that are all the same length and placing them above the current top row of vectors

In the heat equation, what does Q represent?

heat required to raise the temperature

The sun is made up mostly of

plasma material.

Leo drew a force diagram to represent a satellite in orbit around Earth. Which best explains how to correct Leo's diagram?

remove the F(air) vector

In the equation for the gravitational force between two objects, what does G represent?

the gravitational constant

Cecelia dropped a ball from a height of 2 m. The ball fell in a straight path down to the ground. According to Newton's universal law of gravitation, which would change the path of the ball so it traces out the widest curved path possible?

tossing it horizontally at a faster speed

Which statement describes Suchita's final diagram?

The arrow for heat is the widest output arrow.

Luke pulls a sled using a force of 65 N for a distance of 25 m across level ground. The rope Luke pulls forms an angle of 25° with the ground. About how much work does Luke do on the sled?

1,500 J

An object weighs about one-sixth as much but has the same mass on Pluto as on Mercury. If the distance between the asteroids is 2100 kilometers, what is the mass of asteroid Y?

1.1 × 10^16 kg

A vertical spring with a spring constant value of 4500 N/m is compressed 60 cm. A 5.5 kg pumpkin is placed on the end of the spring, and the spring is released. To the nearest whole number, the pumpkin will rise ____ m.

15

A spring that has a spring constant of 1400 N/m is stretched to a length of 2.5 m. If the normal length of the spring is 1.0 m, how much elastic potential energy is stored in the spring?

1575 J

Which are properties of solids? Check all that apply.

2. has a rigid shape that does not change easily 5. has particles that can wiggle but cannot move

Which statements correctly compare the work done to move the couches? Check all that apply.

4. The work for couch 2 is less than the work for couch 3. 5. The work for couch 3 is greater than the work for couch 1. 6. The work for couch 2 is greater than the work for couch 1.

Chen explained that heat engines illustrate only the second law of thermodynamics because they involve the flow of thermal energy from hot to cool areas. His friend Mia disagreed and explained that these engines illustrate only the first law of thermodynamics because they are sometimes 100 percent efficient if they conserve enough energy. Which statement best explains who is incorrect?

Mia is incorrect because machines and engines can never be 100 percent efficient.

Suchita is going to make an energy transfer diagram to represent the energy transformations associated with the flame of a gas stove. The diagram will show that the chemical energy of the fuel transforms into 50 J of chemical energy, 400 J of heat, and 200 J of light. Which statement describes Suchita's final diagram?

The arrow for heat is the widest output arrow.

Which best describes the relationship between internal energy and thermal energy?

Thermal energy is the portion of internal energy that can be transferred.

An 85 kg construction worker has 37,485 J of gravitational potential energy. To the nearest whole number, the worker is ___ m above the ground.

45

An object has a mass of 15 kg and is accelerating to the right at 16.3 m/s2. The free-body diagram shows the horizontal forces acting on the object. What is the frictional force, Ff, acting on the object? Ff= ? Left, Fa= 250 N Right.

5.5 N

Jin knows that the initial internal energy of a closed system is 78 J and the final internal energy is 180 J. He also knows that 64 J of energy are used to do work. To find the heat added to the system, Jin completes the steps below. 1. Add the initial internal energy plus the final internal energy to find the change in internal energy. 2. Add the change in internal energy to the energy used to do work. 3. Write the answer in joules. Which best describes Jin's error?

For step 1, he should have subtracted 78 J from 180 J to find the change in internal energy.

A box is being pulled by two ropes. Eduardo pulls to the left with a force of 500 N, and Clara pulls to the right with a force of 200 N. The box moves because of the two forces applied to it. Leon records the forces and direction of the forces acting on the box in his lab notebook. In the table, which force has the wrong direction?

Kinetic Friction

An object moving in a circle is represented by the motion map. Based on the map, at which point is the object accelerating toward the right?

Z