Chapter 11, Problem 8P

A sprinter of mass m accelerates uniformly from rest to velocity v in t seconds. (a) Write a symbolic expression for the instantaneous mechanical power P required by the sprinter in terms of force F and velocity v. (b) Use Newton’s second law and a kinematic equation for the velocity at any time to obtain an expression for the instantaneous power in terms of m, a, and t only. (c) If a 75.0-kg sprinter reaches a speed of 11.0 m/s in 5.00 s, calculate the sprinter’s acceleration, assuming it to be constant. (d) Calculate the 75.0-kg sprinter’s instantaneous mechanical power as a function of time t and (e) give the maximum rate at which he burns Calories during the sprint, assuming 25% efficiency of conversion form food energy to mechanical energy.