Work and Energy

Kinetic energy formula

KE = ?

• mgh

• F x d

• W/t

• (1/2)mv²

• KE + PE

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Mechanical energy formula

ME = ?

• F x d

• KE + PE

• KE x PE

• W / t

• (1/2)mv^2

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The Law of Conservation of Energy states that

• the force applied to an object multiplied by the object's mass will equal its acceleration.

• if you lay on the couch all day playing video games you don't have to sleep as much since your energy was conserved.

• energy can be converted from one form to another, but cannot be created or destroyed.

• The ability to do work (cause change.) Work is ALWAYS measured in Joules (J)

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What is power? (scientific definition)

• the rate at which work is done

• a push or pull on an object

• how much control you have over others

• the force applied to an object is related to how far it is moved by that force

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The SI unit for power is the _____.

• Joules (J)

• Watts (W)

• Newtons (N)

• horsepower (HP)

If a microwave does 3000 J of work in 3 seconds, its power is

• 9000 W

• 3300 W

• 2700 W

• 1000 W

How much work can be done in 20 seconds by a 800-watt microwave oven?

• 1600 J

• 40 J

• 16000 J

• 4000 J

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If you know power and time, you can calculate work by rearranging the power equation like this:

• Work = Power x time

• Work = Power / time

• Work = time / Power

• Work = Force x distance

The SI unit for work _____.

• Joules (J)

• Watts (W)

• Newtons (N)

• horsepower (HP)

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The ability to do work (cause change.)

• Power

• Energy

• Force

• Horsepower

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