Question

define how is the kinetic energy of a body related to its momentum

Answer 1

☺☺ Hay here is your answer
if massive particle and a light particle have the same momentum, the light one will have more kinetic energy.
the momentum of a particle is given by the equation P = mv where P is the momentum of the particle M is the mass of the particle and V is the velocity of the particle
the ratio of the kinetic energy of two objects having the same momentum is the inverse ratio of their masses .☺☺