Quiz – Length Contraction

A train with a resting length of 125 m is travelling very fast relative to a stationary observer. The train appears 35.0 m long to the stationary observer. How fast is the train moving relative to the observer (in m/s)? Answer using numbers only (i.e. '282000000' for an answer of 2.82 x 10^8 m/s).

A train with a resting length of 175 m is travelling at 3.61 x 10^7 m/s relative to a stationary observer. How long will the train appear to the stationary observer? Assume that the speed of light in a vacuum is 3.00 x 10^8 m/s. Answer in metres, using numbers only (i.e. '1.9' for an answer of 1.9 m).

A train with a resting length of 175 m is travelling very fast relative to a stationary observer. The train appears 137 m long to the stationary observer. How fast is the train moving relative to the observer (in m/s)? Answer using numbers only (i.e. '282000000' for an answer of 2.82 x 10^8 m/s).

A train with a resting length of 275 m is travelling very fast relative to a stationary observer. The train appears 272 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 215 m is travelling very fast relative to a stationary observer. The train appears 209 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).