Chapter 11, Problem 11.50

(choose chapter or problem)

|gflES3 A sprinter of mass m accelerates uniformly from rest to velocity tnn I seconds, (a) Write a symbolic expression for the instantaneous mechanical power v? required by the sprinter in terms of force Fand velocity v. (b) Use Newtons second law and a kinematics 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 sprinters acceleration, assuming it to be constant. (d) Calculate the 75.0-kg sprinters instantaneous mechanical power as a function of time / 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.