How long would it take a push on end of a titanium bar to be felt on the other end, if it were on the moon?

Question

The moon is just used for distance, ignore all problems of rotation and gravitational interference and such.

Answer 1

The mass of the titanium bar is the same, regardless of its weight due to gravitation in any given location. So, the answer is: the same amount of time as anywhere else.

Answer 2

The impulse would travel with the speed of sound in titanium, whatever that is.

Answer 3

Paul is correct as far as he goes, but for a numeric answer;

One source I found list the speed of sound in titanium as 6.07km/s , if we take the distance form the Earth to the Moon (I think that is what you are talking about, but it is not really clear from the way you said it) as roughly 385000km, then the time would be 385000 / 6.07 =  63,400 seconds, about 17 hours and 37 minutes.

Answer 4

The speed of sound in a solid is v = sqrt(Y/rho) for compression waves and v = sqrt(G/rho) for shear waves, where Y is Young's modulus, G is the shear modulus, and rho is the mass density. Plug in the numbers for Ti and the distance to the moon and you will have your result.