Time Distance Speed Calculations
Distance = Speed × Time
Units of Measure:
Time:
Hours
Minutes
There are 60 minutes in an hour so convert these times in
minutes to hours (in decimal notation).
Minutes to hours
Write as a fraction compared
with 60 minutes (in an hour)
30 = 0.5 hrs
30 minutes
60
15 minutes
15 = 0.25 hrs
60
Hours to minutes
Multiply by 60
2 hours
2× 60 = 120 mins
0.75 hours 0.75× 60 = 45 mins
Time Distance Speed Calculations
Distance = Speed × Time
Units of Measure:
Distance:
Speed:
Kilometres
Miles
Metres
Kilometres per hour
Miles per hour
Metres per second
Means ÷
km/hr
miles/hr
m/s
The calculation is given by the units of measure
Speed =
Distance
Time
Time Distance Speed Calculations
Distance = Speed × Time
D=S×T
Use this formula to find the distances for:
1. 20 miles per hour for 2 hours
20 × 2
40 miles
2. 60 miles per hour for 4 hours
60 × 4
240 miles
3. 40 kmph for 30 minutes
4. 80 miles per hour for 15 minutes
5. 42 km per hour for 10 minutes
40 × 30
60
80 × 15
60
42 × 10
60
20 km
20 miles
7 km
Time Distance Speed Calculations
Distance = Speed × Time
Using what we have learnt from rearranging equations
If D = S × T
then
D =S×T
and
D =S×T
Time Distance Speed Calculations
Speed = Distance
Time
Use this formula to find :
240 = 60 km per hour
1. A train travels 240 km in 4 hours
4
What is its average speed?
2. A plane flies over two cities that are 63 miles apart.
The journey takes 7 minutes. What is its average speed?
63 = 9 miles per minute
Answer in miles per minute
7
3. An athlete can run 100 metres in 12 seconds. Calculate the
100 = 8.3 m per second
athlete’s speed.
Answer in metres per second and 1 d.p. 12
4. A cheetah took 6 seconds to run 150m. How fast did it run?
Answer in metres per second
150 = 25 m per second
6
Time Distance Speed Calculations
Time = Distance
Speed
Use this formula to find :
1. A man ran 400 m at an average speed of 8 m/s
400 = 50 seconds
How long did he take?
8
2. A coach travels 120 miles at an average speed of 40 mph.
How long did it take?
120 = 3 hours
40
3. A walker travels a distance of 3 km at a steady speed of 4km.
Find how long he takes in minutes. 3 = 0.75 hrs
0.75× 60 = 45 mins
4
4. A cyclist travelled 6 km at 18 kmph.
Find how long he takes in minutes. 6 = 0.3 hrs
0.3× 60 = 20 mins
18
.
.
Time Distance Speed Calculations
A delivery van sets off at 07:45 to deliver a package 20 miles
from the store. It arrives at the customer at 08:10
a) Calculate the van’s average speed in miles per hour
25 = 0.4167 hrs
20 = 48 miles per hour
60
0.4167
The van’s average speed on the return journey is 25 mph.
b) How long does the return journey take?
Give your answer in minutes. 20 = 0.8 hrs
0.8× 60 = 48 mins
25
c) Calculate the van’s average speed for the whole journey.
40 miles for (25 + 48) = 73 minutes
73 = 1.2167 hrs
40 = 32.9 miles per hour
60
1.2167