Assignment:
Question 1. A supersonic jet traveling at Mach 3 at an altitude of 20000m is directly overhead at time t=0.
A) How long will it be before the ground observer encounters the shock wave?
B) Where will the plane be when it is finally heard?(Assume an average value of 330m/s for speed of sound in air).
Question 2. Expectant parents are thrilled to hear their unborn baby's heartbeat, revealed by an ultrasounic motion detector. Suppose the fetus's bentricluar wall moves in simple harmonic motion with amplitude 1.8mm and frequency 115 per minute.
A) Find the maximum linear speed of the heart wall. Suppose the motion detector in contact with the mother's abdomen produces sound at precisely 2 MHz, which travels through tissue at 1.5km/s.
B) Find the maximum frequency at which sound arrives at the wall of the baby's heart.
C) Find the maximum frequency at which reflected sound is received by the motion detector.
(By electronically "listening" for echoes at a frequency different from the broadcast frequency, the motion detector produces beeps of audible sound in synchronization with the fetal heartbeat.)
Question 3. Two ships are moving along a line due east. The trailing vessel has a speed of 64.0km/h relative to a land-based observation point, and the leading ship has a speed of 45.0km/h relative to the same station. The trailing ship transmits a sonar signal at a frequency of 1200Hz. What frequency is monitored by the leading ship? (Use 1520m/s as the speed of sound in ocean water).