Question

A number of bullets are fired in all possible directions with the same initial velocity $u$. The maximum area of ground covered by bullets is

• A. $\pi {\left(\frac{u^2}{g}\right)}^2$
• B. $\pi {\left(\frac{u^2}{2g}\right)}^2$
• C. $\pi {\left(\frac{u}{g}\right)}^2$
• D. $\pi {\left(\frac{u}{2g}\right)}^2$

Answer 1

The correct option is A $\pi {\left(\frac{u^2}{g}\right)}^2$

A bullet fired at angle ${45}^{\circ }$ will fall maximum away, and all other bullets will fall with this bullet fired at ${45}^{\circ }$.
$R_{max}=\frac{u^2}{g}$
Maximum area covered $=\pi (R_{max}{)}^2=\pi {\left(\frac{u^2}{g}\right)}^2$.