A man is traveling 3 MPH. A buses passes going in the same direction at 30 MPH. How fast does the man appear to be going?

Question

 Math Problem.

Answer 1

Well, consider what happens between time=0 and time=1 hour.

 

The man has traveled 3 miles.  The bus has traveled 30 miles in the same direction.

 

From the ground, the man appears to travel 3 MPH (that was given). 

 

From the man's perspective, he is still with himself as he was when he started, so only the ground and the bus appear to have moved.

 

From the bus, it looks like the man (who started at the same position as the bus) is now 27 miles behind the bus, so he has travelled 27 MPH in the opposite direction.  Also, from the bus, the ground looks like it has traveled 30 miles in the opposite direction in that hour (30 MPH).

 

Now, to stretch your mind just a bit, realize that the Sun doesn't revolve around the Earth, but the Earth revolves around the Sun.  And -- the Sun is moving though space.  And all the stars are moving in relation to each other.  Is there any place in all of outer space that is "fixed?"