+30p While a police car moves at a speed of 30m / s, the driver hears at a single-note frequency of 650Hz. One of the police cars passes in front of someone waiting in the traffic light and gets closer to the other. Calculate the wavelengths and frequencies of a) approaching, b) driving away sirens.

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg