What is the SI unit of power?

Two cranes lift identical loads to the same height, but one crane finishes in less time. Which quantity must be different?

Which statement best describes power in mechanics?

Which unit relationship is correct for power?

A machine transfers the same energy in half the time. What happens to its average power?

A 1000 W appliance and a 500 W appliance are not necessarily ranked by total energy transferred unless you also know the

In the equation P = W/t, what does t represent?

If two motors have the same power but one runs for a longer time, which quantity is larger for the motor that runs longer?

A motor does 2400 J of work on a conveyor belt in 8.0 s. What is its average power?

A winch transfers 7200 J of energy in 60 s. What is the winch's average power?

A small elevator motor does $1.8\times 10^5$ J of work in 300 s. What is its average power?

A machine transfers $4.5\times 10^4$ J of energy in 15 s. What power does it deliver?

A spring launcher transfers 900 J of energy to a cart in 0.50 s. What is the average power during the launch?

A device transfers $3.6\times 10^6$ J of energy in 2.0 h. What is its average power?

A motor does 15,000 J of work in 2.5 min. What is the motor's average power?

A lift transfers $6.0\times 10^5$ J of energy in 40 s. What is the lift's average power?

A launcher does $1.2\times 10^4$ J of work in 0.20 min. What average power does it produce?

A motor transfers $2.5\times 10^3$ J of energy in 5.0 s. What is its average power?

A pump does $8.4\times 10^4$ J of work in 70 s. What average power does the pump deliver?

A crane motor transfers $3.2\times 10^6$ J of energy in 400 s. What is the motor's average power?

A tractor pulls a sled with a constant forward force of 250 N while the sled moves at 12 m/s. What power is delivered to the sled?

A cart is pushed with a constant 80 N force while moving at 3.5 m/s in the direction of the force. What power is supplied?

A boat engine provides a constant 1200 N forward force while the boat moves at 0.75 m/s. What power goes into moving the boat?

A hoist lifts a 15 kg load at a constant upward speed of 0.40 m/s. Using g = 9.8 m/s², what power is needed to lift the load?

A 75 W motor runs for 120 s. How much work does it do if its power output is constant?

A machine must do $1.5\times 10^5$ J of work at a constant power of 750 W. How long will it take?

A worker lifts an 8.0 kg box at a constant speed of 0.50 m/s. Using g = 9.8 m/s², what power is required?

A pump does $4.8\times 10^4$ J of work at a constant power of 600 W. How much time does the work take?

Use the table. Which device transfers the most energy during the time shown?

Use the table. Which device transfers the greatest amount of energy over its listed operating time?

Use the table. Which machine transfers the most energy in the time shown?

Use the table. Which device transfers the most energy during the listed time?

Use the table. Which appliance transfers the greatest energy in the time shown?

Use the table. Which machine transfers the most energy over its listed time?

Use the table. Which device transfers the most energy during the time shown?

Use the table. Which machine transfers the greatest amount of energy?

A student lifts the same backpack the same vertical distance in 6.0 s and then in 18 s. Compared with the 6.0 s lift, the 18 s lift has

Elevator A and elevator B raise identical loads through the same height. A takes 12 s and B takes 24 s. Compared with B, A does

Two motors each transfer 600 J of energy. Motor X takes 5.0 s, and motor Y takes 10 s. Which comparison is correct?

Appliance A is rated 1000 W and runs for 2.0 min. Appliance B is rated 500 W and runs for 4.0 min. Which statement is correct?