Special relativity, time dilation and rockets

[mikep1992]

Homework Statement

Lights are placed at points A and B, which are 100m apart as measured in the rest frame of the earth. As a rocket moving at speed v = 3/5c, passes point A the light turns on. As the rocket passes point B, the second light turns on.
As read on the rockets clock, the time difference between the events was Δt_r. Clocks synchronized in the rest frame of the Earth measure a time interval Δt_e between the events.

a) Determine Δt_e.
b) Determine Δt_r using time dilation.

Homework Equations

Δt_e = d/v (where d = 100m)

Δt_r = 1/sqrt(1-(v/c)^2)Δt_e

The Attempt at a Solution

Δt_e = 5.56 x 10^(-7) s
Δt_r = 6.94 x 10^(-7) s

However I'm unsure as to whether I've used the right times for the different values of t.

 

[VanOosten]

looks good to me, i got the same answers