3 A rocket moves at a speed of 242 m/s directly toward a stationary pole (through stationary air) while emitting sound waves at frequency f = 1250 Hz. (a) What frequency f' is measured by a detector that is attached to the pole? (b) Some of the sound reaching the pole reflects back to the rocket as an echo. What frequency f does a detector on the rocket detect for the echo?

Pr5. Two identical loudspeakers are located at points (-10,0,0) and (0,0, 10) of our coor- dinate system, where the numbers in the brac- kets correspond to the (r, y, z) coordinates of the points, expressed in meters. The loudspeakers are driven by the same oscillator with a frequ- ency of 170 Hz. The speed of sound in air can be considered 340 m/s. a) Give the coordinates of those points loca- ted on the positive r axis where the sound waves coming from the two loudspeakers interfere con- structively. b) A receiver is started to move slowly from the origin (0,0,0) along a path lying in the r-y plane so that it receives constant sound intensity throughout its slow motion. What is the shape of the path the receiver should take?

AM radio signals are broadcast at frequencies between 550 kHz (kilohertz) and 1600 kHz and travel at 3 x 10^8 m/s. a) What is the range of wavelengths for those signals? b) FM frequencies range between 88 MHz (megahertz) and 108 MHz and travel at the the same speed. What is the range of the FM frequencies.

Two progressive waves yj = A sin( 4 x - ot) and y2 = A sin( 2" x – ot – 5) travel in the same direction. Calculate the velocity of the wave produced as a result of interference of these two waves. Take A = 5 cm, 1 =8.7 m and w =12.7 rad/s (radian per second). Give your answer in Sl units.