# energy, work and momentum

## 15 terms

### What is 'work'?

The work done on an object is the energy transferred to an object in the direction of the force

### what effects the work done?

the force and the distance moved

### what is the equation to calculate work done?

Work done (J) = Force (N) x distance moved in the direction of the force (M)

### what is the equation for the change in GPE?

Chane in GPE = wieght (N) x change of height (M)

Heat energy

### What is kinetic energy?

The kinetic energy of an object is the energy it has due to its motion

### what effects an object's kinetic energy?

its mass and its speed

### what is the equation for kinetic energy?

Kinetic energy (J) = 0.5 x mass (Kg) x speed2 (m/s2)

### what is stored in a rubber band when it is stretched?

elastic potential energy

### what is an elastic object?

an object which regains its shape after being stretched or squashed

### what is the law of the conservasion of momentum?

Momentum is conserved in any collision or explosion provided no external forces acts on the objects that collide or explode

### what is the equation for momentum?

Momentum = mass x velocity

### what is the equation which shows us that two objects explode with an equal and opposite force?

(mass of A x velocity of A) = - (mass of B x velocity of B)

### what is the effect of a 'crumple zone'?

it increases the impact time, therefore decreasing the force

### What is the equation for the force in a collision or explosion?

Force = change of momentum ~ (divided by) ~ time taken