Question

A satellite dish is orbiting the earth 980km above earth's surface. A receiving dish is located on earth such that the line from the Satellite to the dish and the line from the satellite to earth's centre form an angle of 24 degrees. If a signal from the Satellite travels at 3x10^8 m/s, how long does it take to reach the dish? Round your answer to the nearest thousandth of a second.

Answer 1

You can use trig here

Answer 2

@jayzdd Do I use sine law or cosine law for this question?

Answer 3

radius of earth is about 6,371 km

Answer 4

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Answer 5

lets use law of sines

Answer 6

Okay

Answer 7

sin(24) / 6371 = sin(x) / ( 980 + 6371)

Answer 8

okay so...
980 +6371 =7351

7351(sin24) / 6371

Answer 9

x=0.469

Answer 10

@jayzdd am i right so far?

Answer 11

yes, now take inverse sine

Answer 12

x=sin-1(0.469)
x=27.9

Answer 13

now what do i do?

Answer 14

distance= rate* time

Answer 15

which number is the rate and which is the time?

Answer 16

rate is the speed at which light travels

Answer 17

but i dont think we did the law of sines correctly.
note that this is a 'angle side side' case, and its an ambiguous case, there are two solutions.

Answer 18

i mean we did the law of sines correctly, but there are two solutions to this triangle

Answer 19

the angle made by the satellite and the center of the earth is an obtuse angle

Answer 20

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Answer 21

How do I find it?

Answer 22

we can subtract 180 from the angle we got before

Answer 23

180-27.9 = 152.1

Answer 24

correct, and then we can use law of sines again to find the length from the satellite to the dish