What is the relation between kinetic energy and momentum?

Explanation

Kinetic energy of a body of mass m is given by, `K = 1/2 mv^2`
Multiply and dividing R. H. S. by m we get, `K = ((mv)^2)/(2m) = (p^2)/(2m)`
Hence, `K = (p^2)/(2m)` which gives required relation.