# Homework Help: Substended angle, diameter question

1. Sep 18, 2011

### jehan4141

We are on lesson 1 and 2, which are vectors and kinematics only. We haven't covered anything else, yet the professor assigned us this problem. Can anybody help me? I have searched google and have yet to understand this problem. Thank you!

To an observer on earth, the moon, which is 3.8x10^5 km away, substends an angle of 0.52 degrees. What is the moons diameter?

2. Relevant equations
I found on google that S=R x theta

3. The attempt at a solution
The answer is 3500 km, but no matter what configuration I put these values into the equation, I still don't get the right answer.

2. Sep 18, 2011

### Spinnor

I think you have to convert the angle in degrees to an angle in radians for the formula to work? Try that.

3. Sep 18, 2011

### jehan4141

thank you! yes that works!!!

4. Sep 18, 2011

### Ouabache

Last edited by a moderator: Apr 26, 2017
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