physics
posted by Alex .
Calculate the difference between the magnitude of the gravitational force and the magnitude of the normal force exerted on a 100 kg object at the equator. Which of the two forces is equal in magnitude to the weight of the object?

The "normal force" is the measured weight.
Gravitational force MINUS weight equals the centripetal force, M V^2/R
where R is the radius of the Earth and V is the Earth rotational velocity at the equator, 464 m/s
For a 100 kg object, the difference is
100*(464)^2/6380*10^3 = 3.8 N
which is about 0.85 pound.