5.Work, Energy, Power

Question 1

Conservation of Energy

Answer 1

In a closed system with no external forces the total energy of the system before an event is equal to the total energy of the system after the event. The energy does not need to be in the same form after the event as it was before the event.

Question 2

Efficiency

Answer 2

The useful output (e.g. power, energy) of a system divided by the total output.

Question 3

Gravitational Potential Energy

Answer 3

The energy gained by an object when it is raised by a height in a gravitational field.

Question 4

Kinetic Energy

Answer 4

The energy an object has due to its motion. It is the amount of energy that would be transferred from the object when it decelerates to rest.

Question 5

Power

Answer 5

The work done or energy transferred by a system divided by the time taken for that to be done.

Question 6

Work Done

Answer 6

The energy transferred when a force moves an object over a distance.