Question

derive the relation between kinetic energy of a body and its momentum

Answer 1

Starting with KE = (1/2)mv^2  

Multiply both sides by m  

KE.m = (1/2)m^2v^2  

Since p=mv, p^2 = m^2.v^2, so replace m^2.v^2 by p^2:  

KE.m = (1//2)p^2  

Divide both sides by m  

KE = (1/2)p^2/m  

= p^2/(2m)