How far is the center of mass of the Earth-Moon system from the center of the Earth? The Earth's mass is 5.97e24 Kg, the Moon's mass is 7.4e22 Kg, and the distance between their centers is 3.8e8m.

Answer 1

draw a line between earth's center E and moon's center M. Let the system center of mass be at C. If EC=x,

5.97*10^24*x = 7.4*10^22*(3.8*10^8-x)
x = 4.65*10^6

Note that C is very close to E. In fact, it is only

Mm/(Me+Mm) = 1.24% of the way to the moon.

Answer 2

if C is too close to earth,steve ans is wrong then.it should be a relatively small value compared to 4.65×10^6

Answer 3

its quite simple .understand as in the concept of moments.f1d1=f2d2...... centre of mass is like c.o.g of a system

Answer 4

but the guy is correct anyway.