Quiz – Special Relativity

What is the Lorentz factor for an object travelling at 22.0% of the speed of light?

What is the Lorentz factor for an object travelling at 9.01 x 10^7 m/s? Assume that the speed of light in a vacuum is 3.00 x 10^8 m/s.

A train with a resting length of 175 m is travelling very fast relative to a stationary observer. The train appears 172 m long to the stationary observer. How fast is the train moving relative to the observer, as a percentage of the speed of light? Answer using numbers only (i.e. '72.5' for an answer of 72.5% of the speed of light).

A train with a resting length of 175 m is travelling very fast relative to a stationary observer. The train appears 172 m long to the stationary observer. How fast is the train moving relative to the observer (in c)? Answer using numbers only (i.e. '0.75' for an answer of 0.75c).

A train with a resting length of 175 m is travelling at 0.770c relative to a stationary observer. How long will the train appear to the stationary observer? Answer in metres, using numbers only (i.e. '1.9' for an answer of 1.9 m).