Question

If radio waves were used to communicate with an alien spaceship approaching Earth at 10% of the speed of light c, Earth would receive their signals at a speed of

Answer 1

Step-by-step explanation:

speed of alien spaceship = .1 c

We shall apply formula of relativistic mechanics to solve the problem

relative velocity =

`(v+v_1)/(1 -(v* v )/(c^2) )`

Here v = v₁ = .1 c

relative velocity = .1c + .1 c / 1 - .1²

= .2 c / .99

= .202 c

The earth would receive the signal at the speed of .202 c .