1. Dynamics and Space Learning Intention You will be able to:
Carry out calculations involving the relationship between speed, distance and time.
Design experiments to determine the average and instantaneous speeds of objects.

2. distance = average speed x time d = v x t
d measured in metres
v measured in m/s
t measured in seconds

3. Alternative way to measure average speed from the BBC
Speeding cars

4. Watch the following video
100 metre race
Now calculate out how fast Mr Bolt was running in m/s. Remember to show your working.

5. Questions
Concorde was a supersonic passenger aircraft which carries over 100 passengers at an average speed of ‘Mach 2’ or 680 metres per second.
Calculate the distance travelled in 10 seconds.

6. 2. After having its batteries recharged, a powered wheelchair can travel for 3 hours at a steady speed of 2 metres per second.
Calculate the distance travelled before its batteries need to be recharged.

7. 3. The London to Glasgow shuttle plane takes 1 hour to
3.The London to Glasgow shuttle plane takes 1 hour to travel the distance of 864 kilometres.
Calculate its average speed in metres per second.

8. 4 The following information is an extract from a railway timetable:
a) Find the average speed in metres per second for the journey from Glasgow to Stirling.
b) Find the average speed in metres per second for the journey from Perth to Inverness.
Station
Time
(24 hour clock)
Distance
(kilometres)
Glasgow
0933
Stirling
1009 51
Perth
1054 48
Inverness
1324
170

9. 5 The distance from London to Paris using the Channel Tunnel is 360 kilometres. The time taken for this journey by car is 5 hours.
(a)Calculate the average speed for the journey.
The distance from London to Paris using a car and the ferry is 360 kilometres. The time taken for this journey is 5 hours.
(b) Calculate the average speed for the journey.

10. 6 A robot in a warehouse moves a total distance of 3 kilometres during an 8 hour shift.
Calculate its average speed in
(a) kilometres per hour (b) metres per second.

11. INSTANTANEOUS SPEED  
The instantaneous speed of a vehicle at a given point can be found by measuring the speed over a very short time as the vehicle passes the point. Provided the time taken is short enough the speed will not change and instantaneous speed can be calculated from distance/time.

12. The length of the car is 4.5m
Can you time, using a stopwatch, how long does it take to cross the finishing line and then calculate its instantaneous speed?
Fast cars crossing the finishing line

13. In each line of the following table there is one missing piece of data
In each line of the following table there is one missing piece of data. Calculate the missing quantity for the three lines, showing full working for each one.
Length of card
(m)
Time to cut beam
(s)
Instantaneous speed
(m/s)
0.05
0.005
0.08
4.0
0.014
2.1

14. 2. A card length 10 cm (0. 1 m) was fixed on top of a trolley
2 A card length 10 cm (0.1 m) was fixed on top of a trolley. The trolley was run through a light gate so that the card cut the beam. The clock attached to the gate showed a time of 0.2 s.
Calculate the instantaneous speed of the trolley.

15. 3 A light gate was set up across the Edinburgh Road.
A car, of length 4.2 m, cut the light beam and the clock showed a time of 0.20 s.
Calculate the instantaneous speed of the car as it passed through the light gate. The speed limit is 40 mph (approximately 18 m/s).
Was the car breaking the speed limit or not?

16. Instantaneous speed (m/s)
Three light gates were connected to a computer. A trolley was run through the light gates, one after the other. The computer read-out stated that the instantaneous speed of the trolley at each of the light gates was as shown below:
Describe what the trolley was doing as shown by these computer readings.
Light gate
Instantaneous speed (m/s) 1
0.54 2
0.76 3
0.98

17. 5 Read the following passage and use it to answer the questions.
“If the Police want to know the instantaneous speed of a motorist, they use a radar gun. Radar stands for RAdio Detection And Ranging. The radar gun consists of a combined transmitter and receiver. The transmitter sends out radio waves which reflect off the metal parts of vehicles. If the vehicle is coming towards the Police, the frequency of the reflected wave is greater than the transmitted wave. If the vehicle is going away from the Police the reflected frequency is lower than the transmitted frequency. The gun is programmed to convert the change in frequency into an instantaneous speed and give the Police a digital read-out.”
What do the Police use to measure a motorist’s instantaneous speed?
How do we get the name radar?
Which parts of a car reflects the radio waves?
What happens to the frequency of the reflected radio waves when a vehicle is coming towards the gun?
What happens to the frequency of the reflected radio waves when a vehicle is going away from the gun?

18. SQA 2008 General Q14.
A walker wears a pedometer. A pedometer is an instrument that measures the distance walked by counting the number of steps taken. The walker measures the distance of one step as 0·8 metres, and enters it into the pedometer.
(a) The walker completes 9000 steps during a walk.
Calculate the distance travelled.
(b) The walker completes his walk in 80 minutes.
What is the average speed of the walker in metres per second?
(c) Give a reason why the distance measured by the pedometer may not be accurate.