energy powerwork

1. principal of ennergy

1.1. cannot created and destroy

1.2. convert one form to another

1.3. total energy is an isolated system

2. At Work

2.1. SI unit -joule

2.2. K.E=1/2mv x mv

2.3. energy is the capacity to do work

3. power

3.1. SI unit =watt(W)

3.2. power is a work done in a unit of time

3.3. the unit power is watt=1 joule/1 sec

4. work

4.1. SI unit=joule

4.2. work is application a force over a distance

4.3. force is equal to the weight of the object