## 1. A compressed or stretch spring possessed elastic potential energy.

### 1.1. Relationship between Work and Elastic Potential Energy

### 1.2. Elastic potential energy = work done = area under the graph = 1/2 Fx

## 2. WORK

### 2.1. Defined as the product of force, F, and displacement,S.

### 2.2. S.I. unit for work - joule (J).

### 2.3. 1 J = 1 Nm.

### 2.4. W = Fs

## 3. ENERGY

### 3.1. Defined as the ability to do work.

### 3.2. S.I. unit for energy is joule (J).

## 4. POWER

### 4.1. Defined as the rate of doing work, W,

### 4.2. The S.I. unit for power is watt (W)

### 4.3. 1 W = 1 J s–1

### 4.4. Power, P = Work done, w Time taken,t

## 5. GRAVITATIONAL POTENTIAL ENERGY

### 5.1. Is the work done to lift an object to a height, h from the Earth’s surface.

### 5.2. Gravitational potential energy = Work done

### 5.3. = Force (F) × Displacement (s) = mgh

## 6. ELASTIC POTENTIAL ENERGY

### 6.1. Is the work done to compress or stretch an elastic material with displacement x from the equilibrium position.

### 6.2. Elastic potential energy = Work done = Average force (N) × Displacement (m) = 1/2 Fx

6.2.1. F is the stretching or compression force in (N) X is the displacement from the equilibrium position in (M)

## 7. KINETIC ENERGY

### 7.1. Is the energy possessed by a moving object.

7.1.1. Kinetic energy = 1/2 mv2

7.1.2. m is mass in kg v is velocity in m s–1