- #1
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- 9
- 1
Homework Statement
A car travels due east with a speed of 45.0 km/h. Raindrops are falling at a constant speed vertically with respect to the Earth. The traces of the rain on the side windows of the car make an angle of 45.0° with the vertical. Find the velocity of the rain with respect to the following reference frames.
(a) the car
(b) the Earth
Homework Equations
n/a
The Attempt at a Solution
I managed to find the answer of part a) which is 17.7 m/s using simple trigonometry although I didn't really understand why the sign was positive.
I found the velocity of the car to be 12.5 m/s and with my diagram got:
sin45=12.5/Vr (Vr= velocity of rain relative to the car)
Vr = 12.7 m/s
For part b, I thought that
velocity of rain relative to car = velocity of car relative to Earth - velocity of rain relative to earth
So, 17.7 = Vre -12.5
So I found the velocity of rain relative to the Earth to be 30.2 m/s.
I can't remember where I got that reasoning for part b from, but is that the only thing that's wrong?
Please help...