Q 11-03-141JEE MainJEE Main 2021 (27 Aug, Shift 2)Easy
A player kicks a football with an initial speed of $25$ m s$^{-1}$ at an angle of $45^\circ$ from the ground. What are the maximum height and the time taken by the football to reach at the highest point during motion? (Take $g = 10$ m s$^{-2}$)
Answer: (A) $h_{max} = 15.625$ m, $T = 1.77$ s
$$h_{max} = \frac{u^2\sin^2\theta}{2g} = \frac{625\times\frac{1}{2}}{20} = 15.625\ \text{m}$$
$$T = \frac{u\sin\theta}{g} = \frac{25\times0.707}{10} \approx 1.77\ \text{s}$$
Solution by Sreeraj P, M.Sc Physics