Question

A cyclist increases his kinetic energy from 11 00 J to 5 200 J in 12 s. How can I calculate his power output during this time?

Answer 1

Speed is the direct consequence of kinetic energy and the work that is done on any body to accelerate it up is stored in the very form. Over here the cyclist has increased his speed accelerating energy i.e the Kinetic energy from 1100 to 5200, hence the useful work done is actually the difference between the energies i.e

Workdone=(Final K.E) - (Initial K.E)

Which is 4100Joules here, and Power is nothing but the rate of doing work, so simply divide the time taken for increasing the speed.

Ans = 341.67 Watts