Question

A body is projected with velocity v of magnitude $\sqrt{gR}$ < V < $\sqrt{2gR}$ at an angle with the radius vector of earth. If at the highest point the speed of the body is v/4, the maximum height attained by the body is equal to

• A.
• B. R
• C.

Answer 1

The correct option is B

R

Where R = radius of earth g = 9.8 m/$s^2$

(Use the appropriate assumptions)

Conservation of angular momentum of the

body about 'O' yield mv (sin 30)R= m$v^2$(R+h)

$\Rightarrow$ $\frac{v}{2}$R = $\frac{v}{4}$(R+h)

$\Rightarrow$ h =R