Work, Power and Energy Review Each table will work as a team to earn points by answering questions. There will be 60 seconds to answer each question from the time I am done reading unless otherwise noted. Answers will be recorded and presented on the whiteboards at each team table. Correct answers will earn the points denoted by the question. Incorrect answers will not be penalized. The choice of category and question will rotate among teams. At Final Jeopardy, each time may wager all of their earned points, or $1000, whichever is greater. The winning team will earn 1 point of extra credit each on tomorrows test.

Strategy Work together with your team. Talk quietly but discuss possible options. Make sure to write down your solution before time runs out. After each question and answer we will have time to discuss and answer questions.

Work, Power and Energy EnergyConservation of Energy WorkPowerPotpourri Q $100 Q $200 Q $300 Q $400 Q $500 Q $100 Q $200 Q $300 Q $400 Q $500 Final JeopardyFinal Jeopardy: Units

$100 Question from Energy ___________ is the energy of an object in motion

$100 Answer from Energy Kinetic energy

$200 Question from Energy Pulling back a rubber band is a form of storing __________ energy

$200 Answer from Energy Potential

$300 Question from Energy Energy is a measure of an objects _________________

$300 Answer from Energy Ability to cause change

$400 Question from Energy What is the kinetic energy of a 15 kg boulder resting at the top of a 12 m cliff?

$400 Answer from Energy 0 J (Not moving = no kinetic energy)

$500 Question from Energy What is the potential energy of a 15 kg boulder resting at the top of a 12 m cliff?

$500 Answer from Energy 1764 J

$100 Question from Conservation of Energy When a ball is thrown directly upward, which of the following is true? A.Its kinetic energy is mostly converted to potential energy. B.Its potential energy is mostly converted to kinetic energy. C.Its kinetic energy is mostly converted to heat.

$100 Answer from Conservation of Energy A. Its kinetic energy is mostly converted to potential energy.

$200 Question from Conservation of Energy If energy can be neither created nor destroyed, what do we mean when we say Dont waste energy!

$200 Answer from Conservation of Energy Dont convert energy into less useful forms, like heat.

$300 Question from Conservation of Energy When a car rolls down a hill, most of its potential energy converts to kinetic energy. Where does most of the rest of it go?

$300 Answer from Conservation of Energy Heat (from friction)

$400 Question from Conservation of Energy A 2 kg object sits at the top of a 10 m hill. How fast will it be rolling at the bottom of the hill?

$400 Answer from Conservation of Energy 14 m/s

$500 Question from Conservation of Energy An object starting with 20 J of potential energy rolls down a hill. At the bottom, 7/8 of the potential energy has been converted to kinetic energy. How much energy (in Joules) was lost due to friction?

$500 Answer from Conservation of Energy 2.5 J

$100 Question from Work Work is a measure of _____________

$100 Answer from Work How much energy is transferred.

$200 Question from Work One unit for work is a Joule. A Joule is equivalent to a _______________

$200 Answer from Work Newton-meter [N-m]

$300 Question from Work How much work is done if a 20 N force is used to slide a box 4 meters?

$300 Answer from Work 80 J

$400 Question from Work How much work is done if Mr. Richter pushes against a boulder with 200 N of force for 5 seconds but the boulder doesnt move?

$400 Answer from Work 0 J

$500 Question from Work How much work is done to lift a 40 kg barbell to a height of 2 m?

$500 Answer from Work 784 J

Daily Double! You have 30 seconds to submit your wagers.

$100 Question from Power Which of the following is not a definition of power? A.The rate of energy transfer B.How many Joules are converted to other forms of energy C.The rate at which work is done D.How quickly energy is converted

$100 Answer from Power B. How many Joules are converted to other forms of energy (this is a definition of work)

$200 Question from Power Which is more powerful, a student that runs up the stairs or a student that walks? Assume they have equal mass.

$200 Answer from Power A student that runs. Same work, less time.

$300 Question from Power Calculate the power of a machine that can do 2400 J of work in 8 seconds.

$300 Answer from Power 300 W

$400 Question from Power How much energy does a 1500 W microwave use if it is on for 40 seconds?

$400 Answer from Power 60,000 J

$500 Question from Power How powerful is a weight lifter who lifts a 400N weight 2 m in 1.6 seconds?

$500 Answer from Power 500 W

$100 Question from Potpourri Which force does the most work?

$100 Answer from Potpourri C

$200 Question from Potpourri Work has the same units as what other quantity?

$200 Answer from Potpourri Energy

$300 Question from Potpourri Complete the sentence: Energy can never be created or destroyed, just __________

$300 Answer from Potpourri Energy can never be created or destroyed, just converted from one form to another.

$400 Question from Potpourri A 1000 kg car and an 1200 kg car roll down a hill. Assuming energy is conserved, which car, if either, will be rolling faster at the bottom of the hill?

$400 Answer from Potpourri Neither. Gravity accelerates all objects the same regardless of mass.

$500 Question from Potpourri An ice skater is gliding across the ice at a constant speed. Is she doing work?

$500 Answer from Potpourri No. No acceleration means no force. No force means no work.

Final Jeopardy: Like all objects, humans need energy to cause change. What unit do humans most often use to describe their own changes in energy?

Final Jeopardy Answer The Calorie (= 4,187 Joules)