A ball having kinetic energy KE, is projected at an angle of $60^{\circ}$ from the horizontal. What will be…
- $\frac{(\mathrm{KE})}{8}$
- $\frac{(\mathrm{KE})}{2}$
- $\frac{(\mathrm{KE})}{16}$
- $\frac{(\mathrm{KE})}{4}$
Solution
$\text { K.E. }=\frac{1}{2} \mathrm{mu}^2$
Speed at heighest point
$\begin{aligned}
& \mathrm{V}=\mathrm{u} \cos 60^{\circ}=\frac{\mathrm{u}}{2} \\ & \therefore \mathrm{KE}_2=\frac{1}{2} \mathrm{~m}\left(\frac{\mathrm{u}}{2}\right)^2 \\ & =\frac{1}{4} \times \frac{1}{2} \mathrm{mu}^2 \\ & =\frac{\mathrm{KE}}{4}
\end{aligned}$
Asked in: JEE Main 2025 (23 Jan Shift 2)