# List of formulas related to Work and energy

## Work

W: work done by a force (j), F: force move a object for a distance s, α: angle between F and movement direction

$$ W = Fs \cos\alpha $$### Example

W_{p}: work by gravity, h: the change in height; w_{ms}:work of friction’s force; W: work by a spring

### Power

P: power (watt, W), t: time of conducting the work W(s)

$$ p = \frac{W}{t} $$### Kinetic Energy

$$ E_k = \frac{1}{2}mv^2 $$#### Kinetic Energy Of A Massive Rotating Body

$$ E_K = \frac{1}{2}Iw^2 $$### Work Energy Principle

v1, v2: speeds of object before and after the change

$$ W = \Delta E_k = \frac{1}{2}mv_2^2 - \frac{1}{2}mv_1^2 $$### Potential Energy

E_{p}: gravitational potential energy (j), m: mass of object (kg)