Question

Special relativity / Moving coordinate frames problem, is this answer correct?

Answer 1

v = 0.8 c mean that v/c = 0.8

Answer 2

Okay, I changed that, and still got roughly the same answer.

Answer 3

But 2 by \(\sqrt {1-0.64}\) cannot be equal to 2!!!!

Answer 4

Inside the square root, you are putting in too many c's. If you say that v = 0.8 c, then you have to remember to cancel the c's in the denominator.