Download Work Energy Extra Practice

Date:____________________________
Name: ________________________________ PHYSICS 11: Work & Power Extra Practice Problem 1:​
How long will it take a 50 kg girl that can generate 935 W to run up a flight of stairs that are 4.5 m high? Problem 2​
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How much work is done by the Earth’s gravitational field on a 10.0 kg mass when the mass drops a distance of 5.0 m? 2​
Problem 3​
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A 2.0 kg puck accelerated at 5.0 m/s​
for 0.50 m across a frictionless air hockey table. How much work was done on the puck? Problem 4:​
A bulldozer pushed a large rock with a force of 5000 N at 2.0 m/s for 20 s. How much work was done? Problem 5:​
How much power does a crane develop doing 60 000 J of work in 5.00 minutes? Problem 6: ​
A 4.00 kg rubber ball drops from a height of 5.00 m to the ground and bounces back to a height of 3.00 m. (a)​
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How much potential energy does the ball lose on the trip down? (b)​
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How much potential energy does the ball regain on the trip back up? (c)​
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What is the net loss of potential energy during the bounce? Problem 7:​
A 0.50 kg rubber ball is thrown into the air. At a height of 20 m above the ground, it is traveling at 15.0 m/s. (a)​
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What is the ball’s kinetic energy? (b)​
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What is its gravitational potential energy relative to the ground? (c)​
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How much work was done by someone at ground level throwing the ball into the air? Problem 8: ​
An airplane passenger carries a 300.0­N suitcase up the stairs, a displacement of 5.50 m vertically and 3.75 m horizontally. How much work does the passenger do? Problem 9:​
A steel ball with mass 5.0 kg is at rest on a smooth, level surface. A constant force acts on it through a distance of 10.0 m causing it to roll at 25 m/s. What is the magnitude of the force? Problem 10:​
A 1200.0­kg car speeds up from 16.0 m/s to 20.0 m/s. How much work was done on the car to increase its speed? Problem 11:​
The amount of output work required to lift a crate with a pulley system is 2200 J. The effort force on the pulley is 40 N. What is the effort distance in meters? Problem 12:​
a.) If you push an object twice as far while applying the same force, you do ___________________ as much work. b.) If you push an object just as far while applying twice the force you do ___________________ as much work. c.) if you lift an object twice as high at a constant velocity, you do ___________________ as much work. Problem 13:​
A 1.20 x 103 kg block starting from rest is accelerated by a 2.20 x 103 N force for a distance of 50.0 m along a horizontal surface. a) How much work was done on the mass? b) What is the final velocity of the mass? Problem 14:​
How long will it take a 50 kg girl that can generate 935 W to run up a flight of stairs that are 4.5 m high? Problem 15:​
A car engine exerts a force of 4000 N to accelerate the car over a displacement of 100 m in 8.0 s. Calculate the power of the engine. Problem 16:​
A car of mass 2000 kg is travelling at 45.0 m/s when the driver spots a policeman ahead. The driver applies the brakes lightly for 3.0 s until he slows down below the speed limit. If the average force applied by the brakes was 1.4 x 104 N, by how much did the kinetic energy of the car change? Problem 17: ​
How much energy is consumed by a 100.0 W light bulb if is left on for 12.0 h? Problem 18:​
Ms. Christy pushes a box of bananas up a hill (see image). She pushes with a force of 10 N up the frictionless incline and takes a break after 2m (a horizontal displacement of 1.5m). She then pushes up another 3 m to the top of the hill with the same force. Calculate the total work done on the box by Ms. Christy when she reaches the top of the hill.