Question

The reading of a spring balance corresponds to 100 N while situated at the north pole and a body is kept on it. The weight record on the same scale if it is shifted to the equator, is
(take, $g=10m/s^2$ and radius of the earth, $R=6.4\times {10}^{6}m$)

• A. 99.66 N
• B. 110 N
• C. 97.66 N
• D. 106 N

Answer 1

The correct option is A 99.66 N

Weight is the force that gravitational attraction of earth exerts towards the center of earth=$mg$

At the equator, an additional centripetal force acts towards it outside which is equal to

$m{\omega }^{2}R=10\times (\frac{2\pi }{T}{)}^2\times (6.4\times {10}^6)$ $=0.33N$

Hence, the net force on body at the equator=Recorded weight $=mg-m{\omega }^{2}R=100N-0.33N=99.66N$