A cyclist together with his bicycle has a total mass of and is moving at a constant…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A cyclist together with his bicycle has a total mass of 80kg and is moving at a constant speed along a straight, level road. Answer the following purely on the basis of reasoning about how kinetic energy depends on mass and speed.
(i) The cyclist allows a pillion rider of mass 40kg to sit on the carrier but keeps moving at the same speed. Qualitatively state how the kinetic energy will change compared with the original situation. No numerical calculation is required.
(ii) Keeping the mass at 80kg, the speed of the cyclist becomes three times the original value. By what factor will the kinetic energy change? Give a brief explanation.
(iii) The cyclist now carries the 40kg pillion rider and simultaneously doubles the original speed. By what factor does the kinetic energy change in comparison with the very first situation? Explain your reasoning clearly.