A large number of bullets are fired in all directions with same speed ' $U$ '. The maximum area on the…

A large number of bullets are fired in all directions with same speed ' $U$ '. The maximum area on the ground on which the bullets will spread is
  1. $\frac{\pi \mathrm{u}^2}{\mathrm{~g}}$
  2. $\frac{\pi \mathrm{u}^4}{\mathrm{~g}^2}$
  3. $\frac{\pi^2 u^4}{g^2}$
  4. $\frac{\pi^2 u^2}{g^2}$

Solution

Area in which bullet will spread $=\pi r^2$ For maximum area, $r=R_{\max }=\frac{\mathrm{u}^2}{\mathrm{~g}}\left[\right.$ when $\left.\theta=45^{\circ}\right]$ Maximum area $\pi \mathrm{R}_{\max }^2=\pi\left(\frac{\mathrm{u}^2}{\mathrm{~g}}\right)^2=\frac{\pi \mathrm{u}^4}{\mathrm{~g}^2}$

Asked in: MHT CET 2023 (13 May Shift 1)

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