Transferring Energy Flashcards
1
Q
State the principle of conservation of energy.
A
- Energy can be stored, transferred between stores or dissipated
- It cannot be created or destroyed
2
Q
What are the four main ways that energy can be transferred between stores?
A
- Mechanically - a force acting on an object, or doing work
- Electrically - a charge doing work
- By heating - energy transferred from a hotter object to a colder object
- By radiation - energy transferred by waves
3
Q
Describe the energy transfers for a ball rolling up a slope.
A
- It does work against the gravitational force
- Energy is transferred mechanically from kinetic store of ball to its gravitational store
3
Q
Describe the energy transfers for a bat hitting a ball.
A
- Bat has energy in its kinetic store
- Some energy is transferred mechanically to the ball’s kinetic store
- Some energy is transferred mechanically to thermal store of the bat and the ball
- The rest is carried away by sound
4
Q
Describe the energy transfers for a rock falling from a cliff.
A
- Assuming there’s no air resistance, gravity does work on the rock
- Therefore, the rock constantly accelerates towards the ground
- Energy is transferred mechanically from the rock’s gravitational store to its kinetic store
5
Q
Describe the energy transfers for a car slowing down.
A
- Energy in kinetic store of car is transferred mechanically due to friction between the tyres and road
- It is then transferred by heating to thermal stores of the car and road
6
Q
Describe the energy transfers for a kettle boiling water.
A
- Energy is transferred electrically from the mains to the heating element of the kettle
- It is then transferred by heating to thermal store of water
7
Q
(Exam-style question)
A
8
Q
Describe how the total energy is affected when there are energy transfers in a closed system.
A
There is no net change to the total energy in the system
