A satelite moves round the earth at constant speed on a circular orbit of radius 8000 km, with a time period of 120 minutes. Calculate its orbital speed in ms-1.
AS Physics homework, thanks.
2007-09-19 05:21:59 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
http://en.wikipedia.org/wiki/Orbital_speed
Scroll down to "Mean orbital speed" for the (very simple) formulas.
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2007-09-19 05:30:25 · answer #1 · answered by tlbs101 7 · 0⤊ 0⤋
Using
v = 2Ïr / T
T = (120 * 60) = 7,200s
r = 8000 * 1000 = 8,000,000m
v = (2Ï(8*10^6)) / (7200)
So, v = 6981.317008
v = 6980 ms^-1 (3 significant figures)
2007-09-19 12:38:20 · answer #2 · answered by tinned_tuna 3 · 0⤊ 0⤋
The length of it's orbit (the circumference of the circle) is
C=2Ïr=2Ï8000 km = 2Ï8000000 m = 16Ï * 1000000 meters
It takes 120 minutes which is 120min. * 60sec./min. = 7200 sec. so it must be travelling at
16Ï * 1000000 meters/7200 sec. = 6981 m/s
HTH
Doug
2007-09-19 12:31:15 · answer #3 · answered by doug_donaghue 7 · 0⤊ 0⤋