Aseismogram shows that p waves travel
a. at the same speed as surface waves.
b. more slowly than s waves.
c. at the same speed as s waves.
d. faster than s waves.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.