9709 P42 - Nov 2011 - Q1
3470
A racing cyclist, whose mass with his cycle is 75 kg, works at a rate of 720 W while moving on a straight horizontal road. The resistance to the cyclist’s motion is constant and equal to \(R N\).
- Given that the cyclist is accelerating at \(0.16 \, \text{m/s}^2\) at an instant when his speed is \(12 \, \text{m/s}\), find the value of \(R\).
- Given that the cyclist’s acceleration is positive, show that his speed is less than \(15 \, \text{m/s}\).
