Q. Which of the following is the reason due to which the weight of an object at the poles is greater than at the equator? Answer:
Gravitational pull is more at the poles
Notes: Weight of an object=mg. If g is less then the weight is less. The value of ‘g’ is less at the equator because of the following two reasons:
The shape of the earth is not perfectly spherical. That's why the radius at the equator is more. Thus, g is less at equator.
The centrifugal force is opposite to g at equator. Since forces are vectors and the resultant vector is minimum when the vectors are opposite to each other, g is minimum at equator. If the earth rotated extremely fast then the centrifugal force and g would have cancelled each other out at equator. Earth is spinning with more angular velocity at equator. It decreases as we move towards the poles. This increased angular velocity at equator produces outward centrifugal force which decreases the effect of g.
Hence the weight of an object is less at equator while it is maximum at poles.