Q 11-03-070JEE MainJEE Main 2024 (8 Apr, Shift 1)Easy
A clock has $75\ \text{cm}$ and $60\ \text{cm}$ long second hand and minute hand respectively. In 30 minutes duration, the tip of the second hand will travel $x$ distance more than the tip of the minute hand. The value of $x$ in metre is nearly (Take $\pi = 3.14$):
Answer: (C) 139.4
In 30 minutes the second hand makes 30 revolutions and the minute hand half a revolution.
$$s_1 = 30\times2\pi(0.75) = 45\pi = 141.3\ \text{m},\qquad s_2 = \pi(0.60) = 1.884\ \text{m}$$
$$x = 141.3 - 1.884 \approx 139.4\ \text{m}$$
Solution by Sreeraj P, M.Sc Physics