a. Explain what is meant by work.
b i. Explain how the principle of conservation of energy applies to a man sliding from rest down a vertical pole, if there is a constant force of friction acting on him.
ii. The man slides down the pole and reaches the ground after falling a distance h = 15 m. His potential energy at the top of the pole is 1000 J. Sketch a graph to show how his gravitational potential energy E_p varies with h. Add to your graph a line to show the variation of his kinetic energy E_k with h.