Question

A man weighs 600N on the equator, but when he moves to the pole he finds a slight increase in his weight. This is because

• A. radius of earth is less at poles since it is not a perfect sphere
• B. radius of earth is more at poles since it is not a perfect sphere
• C. there is no increase or decrease in weight on earth
• D. can’t be said

Answer 1

The correct option is A

radius of earth is less at poles since it is not a perfect sphere

As we know that, g = $\frac{GM}{R^2}$ and weight is the force due to gravity i.e mg. Since the earth is an imperfect sphere, its R is smaller at poles than at equators. As seen above, g is inversely proportional to R. Thus, the value of g increases at poles. And hence, the weight of body also increases.