Question

How does acceleration due to gravity vary at poles and equator?

Answer 1

Dear Student ,
Because:

• The Earth is not a perfect sphere - there's a bulge around the equator;
• It spins, so there's a centrifugal effect at work as you move towards the equator;
• Gravity becomes less as you move up in altitude, thus away from the center of the planet;
• There are differences in the local geology (small effect, <0.01%) .

The acceleration of objects towards earth is a combination of both gravitational acceleration and centripetal acceleration. Centripetal acceleration varies at different latitudes due to complicated rotational dynamics.

There is also a difference in the gravitational acceleration at various altitudes (since g is inversely proportional to r^2), but that difference would be very tiny between palo alto and beijing.

Regards