Question

A particle is projected from the ground with a velocity of $25\, m / s$. After 2 second, it just clears a wall $5\, m$ height. Then angle of projection of particle is $\left[ g =10\, m / s ^{2}\right]$

• A. $30^{\circ}$
• B. $45^{\circ}$
• C. $60^{\circ}$
• D. $75^{\circ}$

Answer 1

Answer: (A)

$u_{y}=u \sin \theta$
$y=u_{y} t-\frac{1}{2} g t^{2}$
or $5=(25 \sin \theta) \times 2-\frac{1}{2} \times 10 \times 2^{2}$
$\therefore \sin \theta=\frac{1}{2}$
or $\theta=30^{\circ}$