Work, Energy and Power Flashcards
Work
When a force F moves a body through a displacement s in the direction of the force, the work W done is equal to the force multiplied by the displacement
Work = Force x Displacement W = Fs
Unit of work
The unit of work is the joule (J)
The joule
One joule is the work done when a force of 1 newton acts for a distance of 1 metre in the direction of the force
1 J = 1 Nm
Energy
Energy (E) is the ability to do work. The amount of energy something has is the amount of work it can do
Unit of energy
The unit of energy is the joule (J)
Principle of conservation of energy
States that energy cannot be created or destroyed but can only be converted from one form to another
Kinetic energy
The kinetic energy (Ek) of a body is the energy that body has due to its motion
Potential energy
The potential energy (Ep) of a body is the energy it has due to its position in a force field
Renewable source of energy
A source of energy that does not get used up is called a renewable source of energy
Power
Power is the rate at which work is done
or
Power is the rate at which energy is converted from one form to another
Unit of power
The unit of power is the watt (W)
1 watt = 1 joule per second
