# Centripetal acceleration at equator

The centripetal acceleration of a person standing at the equator is about 0.03 m s–2.

(Radius of the Earth = 6.4 × 106 m.)

The size of the force R provides a measure of the apparent strength of the gravitational field. Show that the apparent field strength g at the equator differs from that at the poles by about 0.3%.

(0.034 ÷ 9.81) × 100% = 0.35%

I dont understand this. How do we know that the acc at the pole is 9.81, and that 0.034 is the difference in the 2 accerelations?

mgb_phys