Answer all parts related to kinetic energy.
a. (a) Define kinetic energy and write its mathematical expression for a body of mass m moving with speed v.
b. (b) A net force acts on a body and does work on it while the body’s speed increases. Using the ideas of force, acceleration and displacement, explain qualitatively why the work done equals the change in the body’s kinetic energy.
c. (c) A cyclist replaces a 12kg bicycle with a 24kg one but rides at the same speed. How does the kinetic energy of the bicycle change? Give your reasoning.