Suppose you are standing at rest as you watch a train approach you with a whistle that has a frequency of 1600 Hz. Describe the pitch or pitches you hear as the train approaches, passes in front of you, and travels away from you.

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?