Energy
Energy is the ability to do work
Work
Transfer of energy when a force moves through a distance in the direction of force
Force
A Push or a Pull that causes the velocity to change
Law of Conservation of Energy
Energy can be transferred usefully, stored or dissipated, but it cannot be created or destroyed.
Velocity
Velocity is a measure of how fast something is moving in a specific direction.
Speed
How fast an object is moving
Vector
A quantity that has both magnitude and direction
Kinetic store
The energy stored by an object’s movement.
Gravitational potential store
-The energy stored in objects raised above the Earth’s surface.
- This energy exists because of the Earth’s gravitational field
Chemical Store
Energy stores by the chemical bonds between atoms.
Elastic Potential store
The energy stored when an object is being stretched, compressed or sqaushed
Nuclear store
The energy stored in the nucleus of an atom. The energy in the nuclear store can be released by radioactive decay.
Internal (thermal) store
The internal store of energy is the sum of the kinetic energy stored in the particles of an object and the chemical energy stored in chemical bonds between particles in the object.
What happened when an object falls freely?
When an object falls freely, it accelerates due to gravity as it falls.
The force of gravity causes the gravitational potential store to transfer into its kinetic energy store.
What energy stores and transfers happen on a roller coaster?
As a roller coaster climbs an incline, the gravitational potential energy store increases
When an object is moved by a force
Work is done
Formula for Work done
Work done = force applied x distance moved along the line of action of the force.
Work done = Energy transferred
Work done by a force depends on
the size of the force
the distance moved
Work Done to overcome friction is mainly transferred to thermal energy stores by heating
Key Points
Work is done on an object when a force makes the object move
Energy Transferred=Work done
Work done to overcome friction is transferred energy to the thermal energy stores of the objects that rub together and to the surroundings.