Q52 / 75 · JEE Main 2025 (23 Jan Shift 2) · Physics
A ball having kinetic energy KE, is projected at an angle of $60^{\circ}$ from the horizontal. What will be the kinetic energy of ball at the highest point of its flight ?
- A$\frac{(\mathrm{KE})}{8}$
- B$\frac{(\mathrm{KE})}{2}$
- C$\frac{(\mathrm{KE})}{16}$
- Correct answerD$\frac{(\mathrm{KE})}{4}$
Solution
Initial K.E,
$\text { K.E. }=\frac{1}{2} \mathrm{mu}^2$
Speed at heighest point
$\begin{aligned}
& \mathrm{V}=\mathrm{u} \cos 60^{\circ}=\frac{\mathrm{u}}{2} \\
& \therefore \mathrm{KE}_2=\frac{1}{2} \mathrm{~m}\left(\frac{\mathrm{u}}{2}\right)^2 \\
& =\frac{1}{4} \times \frac{1}{2} \mathrm{mu}^2 \\
& =\frac{\mathrm{KE}}{4}
\end{aligned}$
Hence, the correct answer is option: 'D'.