1. Braking Distance and Speed
Group Practical Investigation.

2. The PE staff have loaned us the bikes
The PE staff have loaned us the bikes. Treat them in a way that shows we respect the property and know how to treat other people’s property.

3. Aim: to find out the relationship between speed and braking distance.
Independent Variable: Speed of the bike
Dependent Variable: Braking distance
Controlled – mass of bike and rider, quality of bike, distance over which speed is measured, stopwatch operator, ground conditions.

4. Method: 1. Make sure the rider can ride the bike in a straight line and operate the brakes. 2. Set up a 20 m distance over which the bike will travel at a constant speed. 3. Ride the bike towards the constant speed zone. 4. Start the stop watch as the bike enters the zone, stop as it reaches the 20m line. 5. Brake uniformly at the 20m line and measure to the point where the bike stopped. 6. Repeat 6 times at different speeds.

6. Results. Trial Distance Time Braking distance 1 20 m 2 3 4 5 6
An Excel Spreadsheet is prepared to carry out the calculations for speed and to plot the graph of your results – But you will need to print the graph.

7. Conclusion
What is the relationship between speed and braking distance?
Is it linear (as speed doubles braking distance doubled)?
Does it appear more complex than that?