Modern Physics Problem 10.1.1: Time Dilation


A moving red rectangle simulates a space ship. A space beacon, the vertical green rectangle, emits a light flash when each end passes by.

Question 10.1.1a

A spaceship (red) flies close to a space beacon (green) at 70% of the speed of light (position is given in meters and time is given in 10−5 seconds). The beacon emits light flashes as shown in the animation.  The time shown in the upper left hand corner is the time as measured in the reference frame of the beacon.  Click-drag to measure the size of objects in meters.

Question 10.1.1b


See Giancoli-PA: 26-5.


10.1.1a  Time difference = 0.072 x 10-5 s

10.1.1b  Length of the spaceship = 150 m