Weighing the earth : You are given the following data : g = 9.81 ms^(-2). R_(E) = 6.37 xx 10^(6)m, the distance to the moon R = 3.84 xx 10^(8)m and the time period of the moons revolution is 27.3 days. Obtain the mass of the earth M_(E) in two difference ways.

Weighing the earth : You are given the following data : g = 9.81 ms^(-

1.	Weighing the earth : You are given the following data : g = 9.81 ms^(-2). R_(E) = 6.37 xx 10^(6)m, the distance to the moon R = 3.84 xx 10^(8)m and the time period of the moons revolution is 27.3 days. Obtain the mass of the earth M_(E) in two difference ways.
Answer» Solution :We know that `M_(E) = (gR_(E)^(2))/(G) = (9.81 xx (6.37 xx 10^(6))^(2))/(6.67 xx 10^(-11)) = 5.97 xx 10^(24) kg` The moon is a SATELLITE of the Earth. ACCORDING to Kepler.s Third LAW