Question

How fast do p waves travel through granite?

Answer 1

For granite that would be:

Velocity [m/s]------------Velocity [ft/s]

    5800 - 6100             19000 - 20000

If you would like to know velocity in [km/h]
That would be 5800 - 6100 * 3,6 ≈ 21 600 km/h

I calculated with 6000 m/s