Question

1. A person riding a bicycle on level ground reaches a velocity of 13.4 m/s before

stopping. While braking, the internal energy of the brakes, wheels, and road
increase by 5836 J. What is the mass of the cyclist?

Answer 1

To answer this question, you need to recognize that energy is conserved. The initial energy was kinectic and then transferred to internal; therefore, in this problem, (aka final energy) internal energy = kinectic energy (aka initial energy).

Kinectic energy = 0.5 * m * v^2

5836 = 0.5 * m * (13.4)^2
89.78m = 5836
Mass = 65 kgs