posted by Joe .
A mass of 100g is attached to one end of a massless rod, 10cm in length, which is pivoted about the opposite end. The rod is held vertical, with the mass at the top, and released. The rod swings.
A. What is the speed of the mass at the instant that the rod is horizontal?
B. What is the speed of the mass when it is making an angle of 30 degrees below the horizon?