JEE PYQ: Gravitation Question 11
Question 11 - 2021 (24 Feb Shift 2)
A body weighs 49 N on a spring balance at the north pole. What will be its weight recorded on the same weighing machine, if it is shifted to the equator?
[Use $g = \frac{GM}{R^2} = 9.8$ ms$^{-2}$ and radius of earth, $R = 6400$ km.]
(1) 49 N
(2) 49.83 N
(3) 49.17 N
(4) 48.83 N
Show Answer
Answer: (4)
Solution
At equator: $g’ = g - R\omega^2$. $\omega = \frac{2\pi}{24 \times 3600}$. $R\omega^2 = 6400 \times 10^3 \times \left(\frac{2\pi}{86400}\right)^2 \approx 0.034$ m/s$^2$. $W’ = m(g - R\omega^2) = 49 \times \frac{9.8 - 0.034}{9.8} \approx 48.83$ N.
BETA
