Question

find the work done in increasing the velocity of a body of mass 2 kg from 4 metre per second to 8 metre per second.

Answer 1

By work-energy theorem ,

         Change in kinetic energy of the particle = Work done

Thus,

           Work done in the above case = 1/2m(v2-u2)

                                                              = 1/2 x 2 x (8^2 - 4^2) J

                                                              = 64-16 J

                                                              = 48 J