Question

Calculate the change in kinetic energy of a moving body if its velocity is reduced to one-third of the initial velocity.

Plz guys its urgent!

Answer 1

key to this question is the below equation for the kinetic energy of a moving body..
E = 1/2(mv^2)
where
E = kinetic energy
m = mass
v = velocity

now apply the same equation to the both instance..take the kinetic energy of the 2 instances as E1 & E2

for the 1st instance ..if yhe velocity of the object is v ..then the velocity of the second instance is v/3


divide the 2 equations and we can get a relationship between E1 & E2..

hope this will help you :).ask anything if this is not clear