A truck is moving at 50 m/sec while its horn emits a steady note at 280 cy/sec. A woman is stationary, 150 meters ahead of the truck. A man is in a car, 200 meters ahead of the truck, moving toward the truck at a speed of 30 m/sec. The speed of the sound is 345 m/sec. PART a. Find the frequency heard by the woman. PART b.
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) I will send what I have for this one
A student in a parked car honks the horn, which has a `proper' frequency of 300 Hz. An observer in an approaching vehicle measures the frequency of the sound to be 329 Hz. Calculate the speed of the approaching vehicle. Use 343 m/s as the speed of sound in air.
The ear has a protective overload mechanism called the "acoustic reflex". A sound in excess of about 85 dB causes muscles attached to the eardrum and ossicles to engage, which provides a safety margin of about 20 dB or 30 dB (the equivalent of ear plugs). This reflex takes about 30 ms to 40 ms to cut in, and maximum effect only