Q1. The frequency of an opera singer is 450 Hz. Assume the speed of sound in air is 340 m/s. What is the frequency heard by an observer who is running down the road towards the opera singer with a speed 25.0 m/s?
Q2. Three uniform thin rods, each of length L = 22 cm, form an inverted U. The vertical rods each have mass of 14 g; the horizontal rod has mass of 48 g. Where is the center of mass of the assembly (x, y)?