1

SpeedLearning Objective:

To understand and use formulae involving speed.

How many units of speed can you think of?

2

How fast?

Fastest Snail

Max speed of a 747

Sound

Light

Cruising speed of Concorde

3

How fast?

Fastest Snail

Max speed of a 747

Sound

Light

Cruising speed of Concorde

0.01 km/h

1.08 x 109 km/h

967 km/h

2150 km/h

1238 km/h

4

Miles per hour (mph)

Kilometres per hour (kph or km/h)

Metres per second (m/s or ms-1)

Speed = Distance Time

Or S = DT

S

D

T

5

Speed = Distance Time

S

D

T

Time = Distance Speed

Distance = Speed x Time

6

A man is running at a speed of 8 km/h for a distance of 5200m. Find the time taken in minutes.

S

D

T

7

It has taken an aeroplane 6 hours to travel a journey at an average speed of 500 km/h. How far has it travelled?

S

D

T

8

What is 54 km/h in m/s ?

54 km/h = 54 000 metres / hour

= 54 000 metres / minute 60

= 54 000 metres / second 60 x 60

= 15 m/s

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Page 50Exercise 17