Energy Flashcards
Energy is _______ between stores
transferred
When energy is transferred to an object, energy is…
stored in of the object’s energy stores
When a system changes, what happens?
Energy is transferred
What is a system?
An object or group of objects
What are closed systems?
Systems where matter and energy cannot enter or leave
What is always the net change in total energy of a closed system?
Always 0
A simple pendulum has what type of motion?
Oscillating motion
In a simple pendulum, what is the energy transferred between?
Kinetic energy and gravitational potential energy
Work done = ___ ______
Energy transferred
Give 3 examples of work being done
- Initial force excerted by person to throw a ball upwards does work
- Friction between car’s brakes and its wheels does work (as car slows down)
- Collision between car and stationary object = normal contact force between car and object does work
What is the energy transfer for when a person throws a ball upwards?
Chemical energy → Kinetic energy
What is the energy transfer for when a car brakes?
Kinetic energy → Thermal energy
What is the energy transfer for when a car collides with a stationary object?
Kinetic energy → Elastic potential + thermal energy + sound energy
Energy can be ______ usefully, _____ or _______
Energy can be transferred usefully, stored or dissipated
Energy cannot be ______ or _____
Created or destroyed
Less energy that’s ‘wasted’, more _____ device is
efficient
Name 3 ways we can improve the efficiency of energy transfers?
- Insulating
- Lubricating
- Streamlining objects