Question

Q19
A body is projected at an angle 60° with the horizontal with kinetic energy K. When the velocity makes an angle 30° with the horizontal, the kinetic energy
of the body will be
a k/2
b к/з
c 2K/3
d зк/4​

Answer 1

Answer:

Given,

1/2xm u² = k

Vx = Vcos 30°

Ucos 60°

Ucos 60° = Vcos 30°

V = u/√3

Ke = 1/2xmxv²

Ke = 1/2m (u/√3)

Ke = 1/2m u²x1/3

So the answer is (B) k/3