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These are questions from an exam i took earlier tonight, but do not know if i got them correct.

1) Rain is falling with velocity 30 m/s at an angle of 60° from the vertical and is blowing due east. If a passenger inside of a train (also traveling due east) observes the rain falling at an angle of 30° from the vertical how fast is the train moving?

2) Conceptual: Does a bullet fired on earth and a bullet fired on the moon have the same final velocity?

equations:

Trig rules and vector knowledge...

attempt at solution:

What i'm doing as of now is drawing a right triangle with the hypoteneuse equaling 30 m/s, the angle from the vertical equaling 30° and the angle from the horizontal equaling 60° (a standard 30:60:90 triangle). Then, i'm just using standard trig rules to solve for the "opposite" side which in this case i believe would represent the velocity of the train. If that is a correct solution then the answer should be easily gotten by solving this:

sin30°= x / 30 m/s

30(sin30°) = x

15 = x

A choice on the exam was 14.9 so that is what i chose. I just dont know if that is a valid way to do the problem or not....

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# Rain from the perspective of a moving train and a gun on the moon!

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