Astronomical observations show that the centre of mass of the earth moon system is 4.7x10^6 from the centre of the earth. The distance between the centres if the earth and moon is 384.4x10^6. I don't know whether it means that the gravitational potential at this so called centre of mass of the system is zero or what is the question meaning in saying that the centre of mass of the system , how does it help , what does it imply?
2006-09-16 02:47:31 · 3 answers · asked by Big bird 1 in Science & Mathematics ➔ Physics
wow you people are so clever! I finally managed to understand this. My teacher called me a moron when I asked him this question(even a idiot would be able to do it in a minute) and asked me to go hell!
2006-09-16 03:12:57 · update #1
Mass of Earth x distance from centre = mass of moon x distance
so M(e) x 4.7x10^6 = M(m) x (384.4x10^6 - 4.7x10^6)
ie sum of moments is zero.
You should get a value of about 1/80 of M(e).
2006-09-16 03:05:35 · answer #1 · answered by Auriga 5 · 0⤊ 0⤋
Imagine that the Earth and Moon were on two ends of a mass-less stick. The center of mass is the point at which these two masses balance, so if the distance from the center to the earth's center is x and the distance from the center of mass to the center of the moon is y then
x * e = y * m and
x + y = 384.4X10^6 and
x = 4.7X10^6
use this information to figure the ratio of e/m = y/x
2006-09-16 09:55:18 · answer #2 · answered by rscanner 6 · 0⤊ 0⤋
Mass of MoonM(m)=mass of earthM(m)/6.
2006-09-16 09:55:18 · answer #3 · answered by coolcollegian.dhams 1 · 0⤊ 0⤋