A 0.75 kg ball is released from rest 3.0 m above the floor, and air resistance is negligible. Which relationship reaches its speed just before impact in the fewest steps?

A rope pulls a sled 12 m across level snow with a 40 N force at 25 degrees above the direction of motion. Which relationship directly gives the rope's work on the sled?

A 900 kg car speeds up from 10 m/s to 18 m/s on a level road. Which relationship most directly gives the net work done on the car?

An elevator motor lifts a 500 kg elevator upward 8.0 m at constant speed in 16 s. Which relationship gives the motor's average power against gravity?

A sliding crate of mass m stops because friction acts over distance d. Which relationship gives the magnitude of the friction force if its starting speed is $v_i$?

A skateboarder coasts up a frictionless ramp and momentarily stops at height h above the start. Which relationship finds h from the starting speed v?

A crane raises a crate at constant speed through vertical distance h. Which relationship gives the work done by the cable on the crate?

A cart rolls down a hill with friction, starting from rest at height h and ending with speed v. Which relationship gives the internal energy generated?

A student writes, 'At the bottom of the roller coaster drop, the potential energy has been used up and is gone.' Which correction is best?

A student says, 'If a bicycle's speed doubles, its kinetic energy doubles.' Which correction should replace that statement?

A student writes, 'Carrying a backpack along a level hallway does positive work on it because the backpack feels heavy.' What is the physics correction?

A student says, 'Power and energy mean the same thing because both are measured in watts.' Which correction is right?

A student says, 'Friction destroys energy when a sliding box slows down.' Which correction is best?

Two balls are dropped from the same height with negligible air resistance. A student says the heavier ball lands faster because it had more potential energy. What is the correction?

A student writes, 'When I push a box at constant speed, my work disappears because the box's kinetic energy does not change.' Which correction is right?

Use the energy bar chart for a 2.0 kg cart. What is the cart's speed at point B?

Use the energy bar chart. What gravitational potential energy is missing at point B?

Use the energy bar chart for a 5.0 kg object. What is the object's height at point B? Take $g=9.8m/s^2$.

Use the energy bar chart for a skateboarder. What internal energy is generated by point B?

Use the energy bar chart for a 0.50 kg ball. What is the ball's speed at point B?

Use the energy bar chart. How much energy has been dissipated into internal energy by point B?

Use the energy bar chart for a 3.0 kg cart. What is the cart's speed at point B?

Use the energy bar chart for a 2.0 kg object. What height above the zero level does point B represent? Take $g=9.8m/s^2$.

A 60 kg student climbs stairs with a vertical height of 4.0 m in 5.0 s at a steady pace. Take $g=9.8m/s^2$. What is the student's average power against gravity?

A 1200 kg car slows from 20 m/s to 12 m/s on a level road. What net work is done on the car?

A 50 N rope pulls a box 6.0 m across a level floor at 30 degrees above the direction of motion. How much work does the rope do on the box?

A 0.25 kg ball is thrown straight upward at 12 m/s. With no air resistance, how high above the release point does it rise? Take $g=9.8m/s^2$.

A 2.0 kg cart speeds up from 3.0 m/s to 7.0 m/s as a compressed spring pushes it. How much work does the spring do on the cart?

A 75 kg hiker gains 300 m of vertical height in 45 min. Take $g=9.8m/s^2$. What is the hiker's average power output against gravity?

A 0.80 kg cart is moving 1.5 m/s at the top of a 2.0 m high frictionless hill. What is its speed at the bottom? Take $g=9.8m/s^2$.

An elevator motor lifts a 400 kg elevator 12 m in 20 s at constant speed. Take $g=9.8m/s^2$. What average power does the motor supply against gravity?

A 5.0 kg load is raised 1.5 m, then raised another 0.75 m, all in 3.0 s. Take $g=9.8m/s^2$. What average power is needed against gravity?

A 10 kg sled moving 6.0 m/s stops after sliding 12 m on level snow. What is the average friction force magnitude on the sled?

A waiter carries a 2.0 kg tray at constant speed up a staircase that rises 3.0 m while running 5.0 m horizontally. Take g = 9.8 m/s². What work does the waiter's upward force do on the tray?

A person lifts a 15 kg box straight upward 0.80 m at constant speed. Take $g=9.8m/s^2$. How much work does the person's force do on the box?

A 70 kg passenger rides an elevator upward 5.0 m. Take $g=9.8m/s^2$. What work does gravity do on the passenger?

A book slides 2.0 m across a level table. What work does the table's normal force do on the book?

A bicycle rolls forward while the brakes exert a backward friction force on the wheels. What kind of work does the braking force do on the bicycle?

A satellite moves in a circular orbit at constant speed, and gravity always points toward the center of the circle. What work does gravity do over one small part of the orbit?

A worker lowers a 10 kg bucket downward 0.50 m at constant speed while pulling upward on the rope. Take $g=9.8m/s^2$. What work does the rope do on the bucket?