# Changing momentum

I can use the equation force = mass × change in velocity ÷ change in time to calculate the size of force involved in changing momentum in a certain amount of time.

# Changing momentum

I can use the equation force = mass × change in velocity ÷ change in time to calculate the size of force involved in changing momentum in a certain amount of time.

## Lesson details

### Key learning points

- The momentum of an object is changed by a resultant force acting over a period of time.
- Force = rate of change of momentum, F=Δp/t = mv – mu/t
- The size of an impact force can be changed when the duration of the impact changes.

### Common misconception

Pupils often confuse the terms force and momentum.

Make explicit the understanding that forces change the motion of an object, and that the motion of an object (that a force can change) can be described by its momentum.

### Keywords

Momentum - is the product of the mass and velocity of an object, p = m v, it is a vector quantity

Initial velocity, u - is the velocity of an object at the start of a phase of motion, represented by u

Final velocity, v - is the velocity of an object at the end of a phase of motion, represented by v

Rate of change of momentum - is the change in momentum per second, this is equal to the resultant force acting on an object

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Video

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## Starter quiz

### 6 Questions

## Exit quiz

### 6 Questions

momentum -

the product of the mass and velocity of an object, $$p = m × v$$

initial velocity -

the velocity of an object at the start of a phase of motion, $$u$$

final velocity -

the velocity of an object at the end of a phase of motion, $$v$$

rate of change of momentum -

the change in momentum per second, equal to the resultant force