11. C Which of the following is a definition of power? A. Power is the rate of change of flux. B. Power is the rate of change of energy. C. Power is the rate of change of momentum. D. Power is the rate of change of displacement. 12. C The graph below shows how the force acting on an object varies with distance 15 F(N) 10 - 5 10 20 30 40 50 60 d (m) What is the work done in moving the object from 20 m to 60 m? A. 50 J B. 100 J C. 400 J D. 900 J