# Different speeds (v=x/t)

I can describe how to calculate average speed, instantaneous speed and relative speed and estimate the speed of everyday things.

# Different speeds (v=x/t)

I can describe how to calculate average speed, instantaneous speed and relative speed and estimate the speed of everyday things.

## Slide deck

## Lesson details

### Key learning points

- Average speed = distance/time
- The speed of sound in air is about 330 m/s.
- Scalar quantities have magnitude only.
- Speed and distance are scalar quantities.
- Relative speed is the speed an object is moving towards or away from another object, which may also be moving.

### Common misconception

Pupils often do not have an understanding of what moving at a particular speed means in the real world, and treat answers as ‘just numbers’.

Use real world examples of speeds through examples and questions asked (N.B. 10 m/s is approximately 20 miles per hour).

### Keywords

Average speed - The average speed of an object is the distance it travels each second (m/s). It is a scalar quantity.

Instantaneous speed - The instantaneous speed of an object is the speed at a particular moment.

Scalar quantity - Some quantities only have magnitude (size), and not direction. This includes distance and speed.

Magnitude - A scalar quantity only has magnitude (size).

Relative speed - The relative speed of objects is the difference in their speeds taking into account direction of movement.

### Content guidance

- Contains subject matter which individuals may find upsetting.

### Supervision

Adult supervision suggested.

### 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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## Worksheet

## Starter quiz

### 6 Questions

1.5 m/s

3 m/s

6 m/s

30 m/s

80 m/s

500 m/s

## Exit quiz

### 6 Questions

the average distance travelled each second

the speed of an object at a particular moment of time

the size of a quantity

a quantity that has only magnitude (not direction)

the speed of one object compared to the speed of another object

3 m/s

1.5 m/s

6 m/s

0.5 m/s