Fall 2009
Assignment 3: Due Friday, October 3.
1. I measure a meter stick that
is moving in my frame to have a length of 0.6m.
How fast is the meter stick moving relative to me?
2. A person in the frame of the
meter stick in #1 above measures another meter stick that’s at rest in my
frame. How long will it appear to be to
him?
3. Two events occur in my
frame, frame A, 1ms apart. They are at x = 0 and x
= 600m, the one at 0m occurring first in my frame. In another person’s frame, frame B, they are
simultaneous.
a) How fast is frame B moving
along the x-axis relative to me?
b) Are they (i.e. B) moving in
the +x or – x direction?
c) How far apart are the two
events in space in frame B.
4. In my frame, frame A, a muon
is moving downward. It takes 10ms in my frame for the muon
to go from the top of a tall mountain to the bottom, 2.4km in my frame.
a) How fast is the muon moving
in my frame?
b) How long will it be between
those two events in the muon’s frame?
c) What will be the distance
from the top of the mountain to the bottom in the muon’s frame?
5. A rocket ship is traveling
in the +x direction in my frame with a speed of 0.5c. In another person’s frame, frame B, it is
traveling in the +x direction with a speed of 0.8c. How fast and in what direction (+ or – x) is
frame B moving relative to me?