Write two points of difference between electric energy and electric power

Two bodies of masses m₁ and m₂ have the same linear momentum. What is the ratio of their kinetic energies?

5 examples of negative work done.

Two identical balls each of mass 4kg are moving towards each other with speeds 2 ms^–1 and 3 ms^–1 respectively. They undergo head on perfectly elastic collision. Then impulse imparted by one ball on other is

A running man has half the kinetic energy that a boy half his mass has. The man speeds up by 1.0ms^–1 and then has the same energy as the boy. What were the original speed of the man and the boy?