Special Relativity and time dilation

[mikil100]

Homework Statement

Two spaceships are traveling with a relative velocity of 1.2x10^8 m/s, both carrying clocks.
According to the captain of each ship, the other captains clock ticks more slowly than his own. By what factor do the clocks disagree?

Homework Equations

1/(1-(v^2/c^2))^1/2

The Attempt at a Solution

The only formula I can think of that brings up the time dilation going on is the Lorenz Factor, as the only given value is the relative velocity of each ship. I interpreted this question as the ships are speeding at a little over 1/3 of the speed of light past each other if they are using each other as a frame of reference, So I simply plugged the velocity (which is relative to each captain, using the other ship as a reference frame) into the equation to get... so the clocks disagree by a factor of 1.291... I am not sure what units I would even place there or if it is just a number with no units.

Is this the correct line of thinking?

 

[Delphi51]

Yes, you are right on track and the factor has no units because it is a ratio of two times.
I get a different number for the answer. I'm old and out of practise so you are probably correct, but do run it through again to check.