DEFINITIONS: MECHANICS 4

1. Work
   When a force F moves 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
   
   
2. The Joule
   One joule is the work done when a force of one newton
   acts for a distance of one metre in the direction of the force.
   1 J = 1 N m
   
   
3. Energy
   Energy is the ability to do work. The unit of energy is the joule (J).
   
   
4. The Principle of Conservation of Energy
   Energy cannot be created or destroyed but can only be converted from one form to another.
   
   
5. Kinetic Energy
   The kinetic energy (Ek) of a body is the energy it has due to its motion.
   
   
6. Potential Energy
   The potential energy (Ep)of a body is the energy it has due to its position in a force field.
   
   
7. Renewable Sources of Energy
   A source of energy that does not get used up is called a renewable source of energy.
   
   
8. 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.
   The unit of power is the watt (W).