Calculate velocity of neon cat whose length is 10cm so that his length contract by 1cm according to stationary observer’s frame of reference.Assume neon cat is travelling at minkowski space.

Question

It has something to do with 4 dimension

Answer 1

The cat is travelling at a relativistic speed for the stationary observer to see a reduction in the cat's length. The observed length is given by L=L0√(1-(v/c)^2) where c is the constant speed of light (about 300000kps) and v is the cat's speed. L0=10 and L=9 so √(1-(v/c)^2)=0.9.

Squaring, 1-(v/c)^2=0.81, v/c=√0.19=0.436 approx and v=0.436c, making v=130800 kps approx. This is about 471,000,000 kph. (The speed of light is more than a billion kph.)