devarshi-dt-logo

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/s² and radius of the earth, R=6.4×10⁶m)

99.66 N

106 N

110 N

97.66 N

Solution:

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 mω²R = 10 × (2πT)² × (6.4 × 10⁶) = 0.33N
Hence, the net force on body at the equator = Recorded weight = mg − mω²R = 100N − 0.33N = 99.66N