SajjadAhmad wrote:
A satellite in a circular orbit rotates around the Earth every 120 minutes. If the Earth’s radius is 4000 miles at sea level, and the satellite’s orbit is 400 miles above sea level, approximately what distance does the satellite travel in 40 minutes?
A. 1400 miles
B. 9210 miles
C. 4400 miles
D. 4120 miles
E. 8000 miles
TPR
This diagram might help
So, the black dot represents the Earth's center.
So, the radius of the satellite's orbit = 4400 miles
circumference of circle = 2πrSo, the circumference of satellite's orbit = 2π(4400) =
8800πGIVEN: the satellite in a circular orbit rotates around the Earth every 120 minutes.
In other words, the satellite travels
8800π every 120 minutes
So, in 40 minutes, the satellite will travel 1/3 of the
8800π mile orbit (since 40 minutes is 1/3 of 120 minute)
Distance traveled = 8800π/3
PRO TIP: Since π ≈ 3.14, we know that π/3 ≈ 3.14/3 ≈ some number a little bit bigger than 1So, 8800π/3 = 8800(π/3) = 8800(a number a little bit bigger than 1) = some number a little bit bigger than 8800
Answer: B
Cheers,
Brent
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