3: Work and Power EXTRA

What is the law of conservation of energy?

According to the law of conservation of energy, energy can be transformed from one form into another or transferred from one region to another, but energy cannot be created or destroyed.

Agree/Disagree - Doing work faster requires more power.

Agree. Power is the rate at which work is done and is calculated by dividing the work done by the time needed to do the work. Therefore, more power is exerted when work is done in a shorter time.

Agree/Disagree - A fast-moving baseball has more kinetic energy than a slow-moving baseball.

Agree. The faster an object moves, the more kinetic energy it has, so the fast-moving baseball would have more energy.

Do you agree or disagree? Energy can change from one form to another.

Agree. When energy is used, it is usually changed from one form to another.

Agree/Disagree - Work is done when you push a book across a table.

Agree. Work is the transfer of energy that occurs when a force makes an object move.

What are different forms of energy?

Different forms of energy include thermal energy, sound energy, electric energy, nuclear energy, and radiant energy.

How are different types of energy used?

Different types of energy are used by transforming it from one form to another.

Agree/Disagree - A book sitting on a shelf has no energy.

Disagree. A book sitting on a shelf has thermal energy. Also, there's gravitational potential energy between the book and Earth.

Do you agree or disagree? If you toss a baton straight up, total energy decreases as the baton rises.

Disagree. If you toss a baton straight up, total energy does not change as the baton rises.

What is energy?

Energy is the ability to cause change.

What must happen for work to be done?

For work to be done on an object, an applied force must move the object in the direction of the force.

How does friction affect energy transformations?

Friction transforms mechanical energy into thermal energy.

What are potential and kinetic energy?

Kinetic energy is the energy a body has because it is moving. Potential energy is stored energy.

How are work and power related?

Power is the rate at which work is done.

How does doing work on an object change its energy?

When work is done on an object, the energy of the object increases.

How is energy related to work?

Work is the transfer of energy that occurs when a force causes an object to move.