Question

If the speed of car decreases by half, by how much with kinetic energy decreases?

Answer 1

KE(kinetic energy) = 1/2 mv^2 ----(i)

if final velocity is v/2

so (KE)2 = 1/2 m(v/2)^2
     (KE)2 = 1/2 m(v^2)/4
     (KE)2 = KE/4


so kinetic energy will decreases by 1/4 times



i hope it will help you
regards

Answer 2

original velocity be -v and original kinetic energy be K.E ...and so on