The momentum of a body increases by 20%. What is the percentage increase in its K.E.?

Options

A. 60
B. 52
C. 44
D. 36

Answer

c

Explanation

`p’=p+(20)/(100)p=(6)/(5)p`
When momentum becomes n times then % change in
`K.E. = (n^(2) - 1)xx100 = ((36)/(25) – 1)x100`
`=(11)/(25)xx100=44%`
Hence correct choice is (c).