The mass of a star like our Sun is 455000 Earth masses, and the mean distance from the center of this star to the center of a planet like our Earth is 7.03 x 10 to the 8th power km.
Treating this planet and star as particles with each mass concentrated at its respective geometric center how far from the center of the star is the center of mass of the planet-star system ? Answer in units of km.
2006-11-14 09:36:20 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The center of mass is given by the eqn:
x = sum(moments)/sum(masses)
Taking the center of the sun as the reference point, (x = 0)----> sum (moments) = 455000Me*0 + 1Me*7.03E8 = 7.03E8(km)Me
sum(masses) = 455001Me
Divide the later into the former and get the answer in km from the sun center.
2006-11-14 09:48:01 · answer #1 · answered by Steve 7 · 1⤊ 0⤋
Think of the Sun-Earth system as a big balance beam. If the masses were equal, the CG would be in the exact centre. If the Sun weighed, say, ten times what Earth does, the CG would be ten times further from Earth as from the Sun. If the Earth is 455000 times lighter, the CG is at 45500/(455000+1) of the way to the Sun (or 1/(455000+1) of the way to Earth from the Sun). Multiply that by the given value of the orbital radius to obtain the results in kilometres.
2006-11-14 09:49:02 · answer #2 · answered by poorcocoboiboi 6 · 0⤊ 0⤋
1/455000 x 7.03 x 10^8 km
2006-11-14 10:46:39 · answer #3 · answered by producer_vortex 6 · 0⤊ 0⤋