If a body passes by a celestial body such as the earth or moon , it gains acceleration known as the slingshot effect, the transfer of energy to the obect that is accelerated redues the energy of the mass being slingshotted (is there such a word) In the case of the earth eg it wopuld reduce its spin speed ever so slightly
Question is , if something as big as the space shuttle used the earth as a slingshot, how many times would such a slingshot have to be done before the earth stopped rotating ?
Thanks to all who offer a reply
2006-10-31 03:09:29 · 4 answers · asked by tiggy 1 in Science & Mathematics ➔ Astronomy & Space
The gravitational assist would reduce the planet's orbital speed, not its rotation on its axis.
How many assists would be needed to make Earth spiral into the Sun? Billions. Trillions. I don't know but it would be a mind bogglingly large number.
OK, I did some math. Rough numbers: mass of Earth about 6E24kg and speed of Earth in orbit is 30km/s, so momentum is 1.8E26. Space shuttle is about 1E5kg, assume each gravitational assist changes the speed of the shuttle by 1km/s, that is a 1E5 momentum change; the amount lost by Earth and gained by the shuttle. So it would take 1.8E26/1E5 = 1.8E21 passes to make Earth fall into the Sun. That is:
1,800,000,000,000,000,000,000 times.
2006-10-31 04:12:58 · answer #1 · answered by campbelp2002 7 · 1⤊ 0⤋
The principal of conservation of momentum says that if the satellite gains momentum, then the planet must lose it.
Momentum is m * v.
The masses of the satellite is so small compared to the mass of the planet that you wouldn't be able to measure the change in momentum of the planet.
Kind of like asking "how much does the earth move downward when I jump up in the air"
2006-10-31 11:19:21 · answer #2 · answered by DanE 7 · 1⤊ 0⤋
Tricky calculation. Given the *huge* difference in mass between the earth and shuttle, you'd probably need several hundred digits of precision.
Best answer would be a bunch. A *biiiiiig* bunch âº
Doug
2006-10-31 11:22:10 · answer #3 · answered by doug_donaghue 7 · 1⤊ 0⤋
Well you have to consider the elliptical effect of the orbit and how close it was to the moon at the point of departure.
The accepted estimate of how long it would take the earth to stop rotating is 874,651,987,783 times, give or take 2.
2006-10-31 11:15:33 · answer #4 · answered by Anonymous · 0⤊ 0⤋