A vinyl record is played by rotating the record so that an approximately circular groove in the vinyl slides under a stylus. Bumps in the groove run into the stylus, causing it to oscillate. The equipment converts those oscillations to electrical signals and then to sound. Suppose that a record turns at the rate of 33 rev/min, the groove being played is at a radius of 12.0 cm, and the bumps in the groove are uniformly separated by 0.161 mm. At what rate (hits per second) do the bumps hit the stylus? I am totally lost on this problem...please help me.