Question

There is a 50 meter long train. It magically goes at 60% the speed of light (0.6c). How long will it appear to be to an outside observer?

Answer 1

Answer

Train length

L=50m

Moving v=0.6c

c is speed of light

So train will appear to be to an outside observer as

$L'=L\sqrt{1-\frac{v^2}{c^2}}$

$L'=50\sqrt{1-\frac{(0.6c)^2}{c^2}}$

$L'=50\sqrt{0.64}=40m$