How much work is needed for a 77-kg runner to accelerate from rest to 11.5 m/s?

Work done is change in kinetic energy. That is work done = K.E(final) -K.E(initial) K.E = (mass*velocity*velocity)/ 2 Given the runner accelerates from rest hence initial kinetic energy is 0 since initial velocity is 0. Final kinetic energy = (77kg*11.5m/s*11.5m/s)/ 2 = 5091.625 joules Hence the work done by the 77kg runner to accelerate from rest to 11.5 m/s is 5.0916 Kilo joules.

Ithink they do have the same properties just in less quantities i think