Question

A body is projected with velocity $24m{s}^{-1}$ making an angle ${30}^{\circ }$ with the horizontal. The vertical component of its velocity after $2s$ is $(g=10m{s}^{-2})$

• A. $8m{s}^{-1}$ upward
• B. $-8m{s}^{-1}$ downward
• C. $32m{s}^{-1}$ upward
• D. $32m{s}^{-1}$ downward

Answer 1

The correct option is B $-8m{s}^{-1}$ downward

$4=24m/s,\theta ={30}^o$

initial vertical component $uy=4\sin {30}^o=\frac{4}{2}$

$uy=12m/s$

after $2s$ $V=uy-gt=12-10\times 2=-8m/s$

$-ve$ shows downward motion.