Work, energy and power

Work done involves…

A force (F) and the distance (x) moved in the direction of the force

Work done has the unit…

Nm or J

1J is equal to…

1Nm

When you do work…

Energy is transferred

Work done is equal to…

Energy transferred

Energy is defined as…

The capacity to do work

The component of force in the direction of motion is…

Fcosx

Kinetic energy is associated with an object as a result of…

It’s motion

For objects travelling at the same speed…

The KE is directly proportional to the mass

For a given object, the KE is…

Directly proportional to the square of its speed

Gravitational potential energy is…

The capacity for doing work as a result of an objects position in a gravitational field

When an object gets higher, GPE is…

Gained

When an object gets lower, GPE is…

Lost

As an object falls…

It’s GPE decreases and it’s KE increases

According to the principle of conservation of energy…

The total final energy is always equal to the total initial energy

The principle of conservation of energy states…

The total energy of a closed system remains constant. Energy can never be created or destroyed, but it can be transferred from one form to another

Power is defined as…

The rate of work done

Power is measured in…

Joules per second or watts

The main reason that some input energy is not converted into useful output energy is…

Due to thermal losses

The greater the efficiency…

The greater the percentage of input energy converted to useful energy