Question

If a stone is thrown with a speed $v_0$ at an angle ${\theta }_0$ with horizontal, find the velocity of the stone when its line of motion makes an angle $\theta$ with horizontal.

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

The horizontal component of the velocity will be constant during projectile motion.

Horizontal component of initial velocity $u_x=v_{o}cos{\theta }_o$

Horizontal component of velocity when the particle makes an angle $\theta$ with horizontal $v_x=vcos\theta$

Hence $vcos\theta =v_{o}cos{\theta }_o\Rightarrow v=\frac{v_{o}cos{\theta }_o}{cos\theta }$