Question

Two paper screens $A$ and $B$ are separated by $150m$. A bullet pierces $A$ and $B$. The hole in $B$ is $15cm$ below the hole is $A$. If the bullet is travelling horizontally at the time of hitting $A$, then the velocity of the bullet at $A$ is $(g=10m{s}^{-2})$.

• A. $100\sqrt{3}m{s}^{-1}$
• B. $200\sqrt{3}m{s}^{-1}$
• C. $300\sqrt{3}m{s}^{-1}$
• D. $500\sqrt{3}m{s}^{-1}$

Answer 1

The correct option is D $500\sqrt{3}m{s}^{-1}$

The bullet exhibits horizontal projectile motion.

Displacement of bullet in vertical direction $y=15cm=0.15m$

Displacement of bullet in horizontal direction $x=150m$

Using equation of trajectory $y=\frac{g{x}^2}{2u^2}$

Or $0.15=\frac{10\times (150{)}^2}{2u^2}$

$⟹u=500\sqrt{3}m/s$