Problem 1 A snowmobile does 120 J of work, applying a force of 13 N. How far does it move?

Problem 2 How much kinetic energy does a train have that has a mass of 500kg, and is moving at 10m/s?

Problem 3 A cell phone charger has an input of 21 J of work from the wall. The work output to your phone is 8 J. What is the efficiency of the charger?

Problem 4 A 300kg airplane travels at a speed of 200m/s. What is its kinetic energy?

Problem 5 ______________ is the rate at which work is done.

Problem 6 A cat jumps 1.0 m and has a potential energy of 98 J What is her mass?

Problem 7 At the top of a roller coaster, the cart has a potential energy of 2100.12 J If the mass of the cart is 430kg, how high is the cart?

Problem 8 A weight lifter lifts a barbell with 40 N of force a distance of 2 m. What is the work being done? If it takes her 3 seconds to lift this barbell, how much power did she use?

Problem 9 For each of the following situations, identify if work is being done: A student sits in a chair A teacher runs up the stairs Your friend slides down a hill You push a box across the floor A student carries her backpack across the room

Problem 10 A chandelier hangs from the ceiling which is a height of 10m weighs 25kg. What is its potential energy?

Problem 11 An ice skater skates for 28 seconds doing 130.4 J of work. How much power did she use?

Problem 12 A box is dragged with a force of 10.2 N to a distance 3.7 m away. How much work is done?

Problem 13 What is the mass of a cheetah running 55m/s that has 30,250J of kinetic energy?

Problem 14 The efficiency of a microwave is 23%. If 775 J of work is input, how much work is output from the microwave?

Problem 15 At which point would the roller coaster have the lowest potential energy? B C A D

Problem 16 Kinetic energy is energy of _________. Potential energy is energy of _______.

Problem 17 What units do we use for the following: Work Ex. speed = m/s Work Energy (both kinetic and potential!) Power Efficiency

Problem 18 A 0.36 kg rock is at the top of a 6.1 m hill. It rolls down the hill losing all its potential energy. At the bottom of the hill, what is the rock’s velocity?

Problem 19 Jack (who weighs 70 N) and Jill (who weighs 65 N) are running up a 7.0 m hill. It takes Jack 10 seconds to go up the hill and Jill 9 seconds to go up the stairs. SHOW YOUR WORK! Who does more work? Who uses more power?

Problem 20: Throwback! Mr. Ludwikowski’s dog runs 283,600 inches at the dog park. How many miles did she go? (1 mile = 5,280 feet)