If the speed of a car is doubled, the kinetic energy of the car is

A constant force is used to keep a block sliding at constant velocity along a rough horizontal track. As the block slides, there could be an increase in its

As an object falls freely, the kinetic energy of the object

An object weighing 15 newtons is lifted from the ground to a height of 0.22 meter. The increase in the object’s gravitational potential energy is approximately

A 0.50‑kilogram ball is thrown vertically upward with an initial kinetic energy of 25 joules. Approximately how high will the ball rise? [Neglect air resistance.]

A 45‑kilogram boy is riding a 15‑kilogram bicycle with a speed of 8 meters per second. What is the combined kinetic energy of the boy and the bicycle?

The work done in moving a block across a rough surface and the heat energy gained by the block can both be measured in

A 50‑kilogram child running at 6 meters per second jumps onto a stationary 10‑kilogram sled on a level frictionless surface. Calculate the speed of the sled with the child after she jumps onto the sled. [Show all work, including the equation and substitution with units.]

Calculate the kinetic energy of the sled with the child after she jumps onto the sled. [Show all work, including the equation and substitution with units.]

After a short time, the moving sled with the child aboard reaches a rough level surface that exerts a constant frictional force of 54 newtons on the sled. How much work must be done by friction to bring the sled with the child to a stop?

Which graph best represents kinetic energy versus velocity for an object accelerating in a straight line?

In the Energy vs. Distance moved graph, total mechanical energy remains constant while kinetic energy increases and gravitational potential energy decreases. Which motion of the block is best described?

A 1000 kg cart moving at 6.0 m/s collides and locks with a stationary 5000 kg cart. What is the combined speed immediately after the inelastic collision?

Using your result for speed, what is the kinetic energy of the combined 6000 kg carts after the collision?

How does the kinetic energy after the collision compare to the total kinetic energy before the collision?

When a force moves an object over a rough, horizontal surface at a constant velocity, the work done against friction produces an increase in the object's

Base your answers to questions 18 through 21 on the information below. The driver of a car made an emergency stop on a straight horizontal road. The wheels locked and the car skidded to a stop. The marks made by the rubber tires on the dry asphalt are 16 meters long, and the car’s mass is 1200 kilograms.

Determine the weight of the car

Calculate the magnitude of the frictional force the road applied to the car in stopping it. [Show all work, including the equation and substitution with units.]

Calculate the work done by the frictional force in stopping the car. [Show all work, including the equation and substitution with units.]

Assuming that energy is conserved, calculate the speed of the car before the brakes were applied. [Show all work, including the equation and substitution with units.]

A 60-kilogram runner has 1920 joules of kinetic energy. At what speed is she running?

As a block slides across a table, its speed decreases while its temperature increases. Which two changes occur in the block's energy as it slides?

If the direction of a moving car changes and its speed remains constant, which quantity must remain the same?

What is the gravitational potential energy with respect to the surface of the water of a 75.0-kilogram diver located 3.00 meters above the water?

As a ball falls freely (without friction) toward the ground, its total mechanical energy

The gravitational potential energy, with respect to Earth, this is possessed by an object is dependent on the object's

A boy pushes his wagon at constant speed along a level sidewalk. The graph shows a constant horizontal force of 30 N over a distance from 0.0 m to 6.0 m. What is the total work done by the boy in pushing the wagon 4.0 meters?

A boy pushes his wagon at constant speed along a level sidewalk. As the boy pushes the wagon, what happens to the wagon’s energy?

A 1.0‑kilogram book resting on the ground is moved 1.0 meter at various angles relative to the horizontal. In which direction does the 1.0‑meter displacement produce the greatest increase in the book’s gravitational potential energy?

A student exerts an average force of 600 N on a rope to lift a 50‑kg crate a vertical distance of 3 m. Compared to the work done by the student, the gravitational potential energy gained by the crate is

A book sliding across a horizontal tabletop slows until it comes to rest. Describe what change, if any, occurs in the book’s kinetic energy and internal energy as it slows.

A pendulum is pulled to the side and released from rest. Which graph best represents the relationship between gravitational potential energy of the pendulum and its displacement from its point of release?

A 250 kg roller coaster car carries a 75 kg passenger and is 20 m above the ground at point A. Neglect friction. What is the total gravitational potential energy of the car-plus-passenger at point A relative to the ground? Use g = $$9.8 m/s^2$$ .

At point B near the bottom of the track, what is the speed of the car-plus-passenger system if it started from rest at A and friction is negligible? Use g = $$9.8 m/s^2$$ and the height of A is $$20 m$$ above B.

Compare the total mechanical energy of the car-plus-passenger at points A, B, and C if friction is negligible.

Which graph best represents how gravitational potential energy near Earth’s surface depends on an object’s height above the surface?

A horizontal 5.0 N force acts on a 3.0 kg mass over 6.0 m on a frictionless surface. What is the change in kinetic energy of the mass over this distance?

As a ball falls freely toward the ground with negligible air resistance, what happens to its total mechanical energy?

A 3.0 kg object is released from rest at point A on a frictionless track where gravitational potential energy is zero at point C. The vertical heights are marked: A at 3.0 m, B at 1.0 m, C at 0.0 m, D at 1.0 m, E at 0.0 m, F at 1.0 m, G at 2.0 m, H at 4.0 m, and I at 4.0 m. What is the gravitational potential energy of the object at point A relative to point C? Use g = 9.8 N/kg.

At point B on the same frictionless track, the object has descended from A and has height 1.0 m. What is the kinetic energy of the object at point B? Use g = 9.8 N/kg.

If released from A, what is the farthest lettered point the object can reach on the track without external forces, assuming no friction?

An object is thrown straight up. Which pair of graphs shows kinetic energy decreasing linearly with displacement while gravitational potential energy increases linearly with displacement?

The graph of gravitational potential energy versus vertical height shows a straight line passing through the origin with positive slope, reaching about 90 J at 4.0 m. What is the gravitational potential energy at 2.25 m?

Using the same graph, determine the mass of the object represented. Assume g = 9.8 N/kg.

What physical quantity does the slope of the gravitational potential energy vs vertical height graph represent near Earth’s surface?

If a heavier object is plotted on the same type of PE vs height graph, which change correctly represents its line compared to the original?

An object falls freely near Earth’s surface. Which graph best represents its kinetic energy as a function of time of fall, neglecting air resistance?

A compressed spring launches a toy cart on a smooth floor. As the spring relaxes, the cart slows to rest. Which energy transformation best describes this process between launch and stop?

A wooden crate is pushed at constant speed across a level rough floor. Which graph best shows total mechanical energy versus time during the push?

Near Earth's surface, how does gravitational potential energy depend on height above the ground?

A 75 kg runner covers 1.8 km in 1.2 $$10^3$$ s. What is the average speed in m/s?

Using the runner’s speed from the previous question, what is the runner’s average kinetic energy?

A 6.8 kg block slides on a horizontal frictionless surface at a constant 6.0 m/s. Approximately what is its kinetic energy?

If the speed of a moving object is doubled, how does its kinetic energy change?

A 155 N box slides up a 5.30 m ramp, rising 1.80 m vertically. Neglect friction. What gravitational potential energy does the box gain?

A car travels at constant speed up a hill from point A to B. As it rises, what happens to its gravitational potential energy and kinetic energy?

A student makes a simple pendulum by attaching a mass to the free end of a 1.50-meter length of string suspended from the ceiling of her physics classroom. She pulls the mass up to her chin and releases it from rest, allowing the pendulum to swing in its curved path. Her classmates are surprised that the mass doesn’t reach her chin on the return swing, even though she does not move. Explain why the mass does not have enough energy to return to its starting position and hit the girl on the chin.

A 65-kilogram pole vaulter wishes to vault to a height of 5.5 meters. Calculate the minimum amount of kinetic energy the vaulter needs to reach this height if air friction is neglected and all the vaulting energy is derived from kinetic energy.

Calculate the speed the vaulter must attain to have the necessary kinetic energy to reach 5.5 meters, assuming all energy converts to gravitational potential at the top.

Which pair of quantities can be expressed using the same units?

A car with mass m possesses a momentum of magnitude p. Which expression correctly represents the kinetic energy, KE, of the car in terms of m and p?

Which statement best explains why a “wet saw” used to cut through fine optical crystals is constantly lubricated with oil?

A 55-kilogram diver falls freely from a diving platform that is 3.00 meters above the surface of the water in a pool. When she is 1.00 meter above the water, what are her gravitational potential energy and kinetic energy with respect to the water’s surface?

As the pendulum swings from position A to position B, what happens to its total mechanical energy? Neglect friction.

Which situation describes a system with decreasing gravitational potential energy?

A 55-kilogram diver falls freely from 3.00 m above a pool. When she is 1.00 m above the water, what are her gravitational potential energy and kinetic energy with respect to the water surface? Take g = 10 N/kg.

As a box is pushed 30 meters across a horizontal floor by a constant horizontal force of 25 N, the kinetic energy of the box increases by 300 J. How much total internal energy is produced during this process?

As the pendulum swings from position A to position B, what happens to its total mechanical energy? Neglect friction.

Which situation describes a system with decreasing gravitational potential energy?

Which statement describes the kinetic energy and total mechanical energy of a block as it is pulled at constant speed up an incline?

A 75-kilogram bicyclist coasts down a hill at a constant speed of 12 m/s. What is the kinetic energy of the bicyclist?

An electrical generator in a science classroom makes a lightbulb glow when a student turns a hand crank. During its operation, this generator converts

A block weighing 40 N is released from rest on an 8.0 m high incline. If 50 J of heat is generated as the block slides down the incline, the maximum kinetic energy of the block at the bottom is approximately

A 75 kg bicyclist coasts down a hill at 12 m/s. What is the bicyclist’s kinetic energy?

An electrical generator turned by a hand crank converts which type of energy to which output?

A 40 N block is released from rest on a rough incline 8.0 m above the horizontal. If 50 J of heat is generated as it slides, what is the maximum kinetic energy at the bottom?

A child starts from rest and reaches 7.0 m/s at the bottom of a frictionless slide. What is the vertical height of the slide?

Two equal-weight students go from the first to the second floor: one via elevator, one via stairs. Compare the gravitational potential energy gained by the walker to the elevator rider.

During an emergency stop, a $$1.5 \times 10^3$$ kg car loses $$3.0 \times 10^5$$ J of kinetic energy. What was its speed when the brakes were applied?

A 55 kg skier is raised 370 m by a chairlift. What is the change in gravitational potential energy?

A box at the top of a rough incline has 981 J more gravitational potential energy than at the bottom. As it slides, 245 J of heat is produced. Determine the kinetic energy at the bottom.

A pendulum with a 7.50 kg mass is released from a position 1.5 m above equilibrium. Neglect friction. What total kinetic energy does the mass have as it passes equilibrium?

During braking on a level road, a car’s kinetic energy is converted primarily into which form?

Using the given data table of speed versus kinetic energy for a runner, which mathematical relationship between kinetic energy and speed is most consistent?

From the runner’s data, estimate the mass of the runner.

A soccer player with less mass than the runner accelerates to 8 m/s. Compare their kinetic energies at the same speed.

A car uses its brakes to stop on a level road. During this process, kinetic energy is primarily converted into which form?

A 7.50 kg pendulum bob is released from rest at position A, which is 1.5 m above equilibrium. Neglect friction. What is the kinetic energy of the bob as it passes through equilibrium?

Using the table: at speeds 0, 2, 4, 6, 8 m/s the kinetic energies are 0, 140, 560, 1260, 2240 J. What is the best-fit mathematical relation between kinetic energy K and speed v?

From the runner data, estimate the mass m of the runner using $$K = \frac{1}{2} m v^2$$ . Use the $$8 m/s$$ , $$2240 J$$ data point.

A less massive soccer player and a more massive runner both reach the same speed of 8 m/s. How do their kinetic energies compare?

Which graph correctly shows the relationship between kinetic energy and speed for a freely falling object?

A 30.4 N force slides a 40.0 N crate 6.00 m along a 30° incline at constant speed to a vertical height of 3.00 m. What is the total work done by the 30.4 N applied force over the incline distance?

For the same crate motion, what is the total increase in gravitational potential energy after sliding 6.00 m to a vertical height of 3.00 m?

As the crate slides up the incline at constant speed, what happens to its kinetic energy?

As the crate slides up the incline at constant speed, what happens to its internal energy due to friction?

A photocell shines light onto a fan, making the blades turn faster with brighter light. Which energy conversion is demonstrated?

In an ideal pendulum swinging freely from A to B with no friction, what happens to the total mechanical energy?

Two pieces of flint rock produce a visible spark when they are struck together. During this process, mechanical energy is converted into

Which graph best represents an object in equilibrium moving in a straight line?

When a mass is placed on a spring with a spring constant of 60.0 newtons per meter, the spring is compressed 0.500 meter. How much energy is stored in the spring?

A shopping cart slows as it moves along a level floor. Which statement describes the energies of the cart?

A 25-gram paper cup falls from rest off the edge of a tabletop 0.90 meter above the floor. If the cup has 0.20 joule of kinetic energy when it hits the floor, what is the total amount of energy converted into internal (thermal) energy during the cup’s fall?

A 3.00-newton force causes a spring to stretch 60 centimeters. Calculate the spring constant of this spring.

Regardless of the method used to generate electrical energy, the amount of energy provided by the source is always greater than the amount of electrical energy produced. Explain why there is a difference between the amount of energy provided by the source and the amount of electrical energy produced.

Which quantities are scalar?

Which energy transformation occurs in an operating electric motor?

A block slides across a rough, horizontal tabletop. As the block comes to rest, there is an increase in the block–tabletop system’s

A compressed spring in a toy is used to launch a 5.00-gram ball. If the ball leaves the toy with an initial horizontal speed of 5.00 meters per second, the minimum amount of potential energy stored in the compressed spring was