GCSE Questions: Forces
Q1. The diagram below shows the horizontal forces acting on a moving bicycle and cyclist.
![](graphics/cyclist.png)
(a)
(i) Which of the following causes force A?
X |
friction |
Y |
gravity |
Z |
weight |
[1 mark]
(ii) What causes force B?
[1 mark]
(iii) The graph shows how the velocity of the cyclist changes during the first part of a journey along a straight and level road. During this part of the journey the force applied by the cyclist to the bicycle pedals is constant.
![](graphics/graphcycle.png)
Describe how and explain, in terms of the forces A and B, why the velocity of the cyclist changes:
between the points X and Y marked on the graph and
between the points Y and Z, marked on the graph.
[6 marks]
(b)
(i) The cyclist used his brakes to slow down and stop the bicycle.
A constant braking force of 140 N stopped the bicycle in a distance of 24 m.
Calculate the work done by the braking force to stop the bicycle.
[4 marks]
(ii) Complete the following sentences.
When the brakes are used, the bicycle slows down. The kinetic energy of the bicycle .................................... At the same time, the ...................................of the brakes increases.
[2 marks]
[13 Marks TOTAL]