Question

What is the sprinters output at 2.0 s, 4.0 s and 6.0 s?

Answer 1

A 59 kg sprinter, starting from rest, runs 47 m in 7.0 s at constant acceleration.?  

What is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s?  

Instantaneous Power is the force times velocity  

P = Fv  

Because the acceleration is constant, the force will be constant as well  

F = ma  

P = mav  

for constant acceleration, the velocity at each time is found using  

v = at  

P = ma(at) = ma²t  

find the acceleration using kinematic equation  

s = ½at²  

a = 2s/t²  

a = 2(47) / 7.0²  

a = 1.918 m/s²  

P(2.0) = 59(1.918²)2.0 = 434.25 W = 0.43 kW  

P(4.0) = 59(1.918²)4.0 = 868.51 W = 0.87 kW  

P(6.0) = 59(1.918²)6.0 = 1302.76 W = 1.3 kW  

I hope this helped.