In vertical circular motion, the ratio of kinetic energy of a particle at highest point to that at lowest point is

Options

A. 5
B. 2
C. 0.5
D. 0.2

Answer

D

Explanation

As we know that the velocity of a particle at lowest point in the vertical circular motion is given by `v_l=sqrt(5gr)and at highest point, is given by `v_h=sqrt(rg)
so, KE at highest point , `(K_h)=1/2m " "rg=(mrg)/(2)`
`and KEat lowest point(K_l)=1/2m" "5" "rg=(5mgr)/(2)`
`So , ratio of ""(K_h)/(K_l)=((mgr)/(2))/((5mgr)/(2))=1/5=0.2`