An ambulance driver traveling at 29.0 m/s (64.9 mph) honks his horn as he sees a motorist ahead on the highway traveling in the same direction. The motorist hears a frequency of 392 Hz and notices that his own speedometer reads 40.3 mph (18.0 m/s). Calculate the frequency that the ambulance driver hears. (Speed of sound is 340 m/s)

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.