You are on an island where a huge explosion at a distance of 500 miles away can be heard, How long (in seconds) does it take the sound to travel to your location? Assume the temperature of the air is 20 oC.

The SR-71 “Blackbird” flies over 2,000 mph. If this planes is flying at 2,000 mph at an altitude of 40,000 ft, how long after it passes over a point on the ground will a groundobserver hear the boom? The speed of sound is 768 mph. This is all the information given.

A bystander hears a siren vary in frequency from 590 Hz to 368 Hz as a fire truck approaches, passes by, and moves away on a straight street. What is the speed of the truck? (Take the speed of sound in air to be 343 m/s.)

A0 ( x=0)   A = A0e-ax I = I0e-2ax HVT (half-value thickness) is the tissue thickness needed to decrease I0 to 1/2 I0. The table below gives the typical HVTs for different tissues.  What is the attenuation of sound intensity by 1cm of muscle and fat?  In the table a comparison between different frequencies on bone is made. Which is better, a higher or lower frequency? Why?

While attending a large fireworks event with music, you decide to stay 1 kilometer away because of the crowds.  However you have a good view, and you can still hear the booms, as well as the music.   Given a speed of sound on a warm moist summer night of 340 m/s, select those that apply.     The music is out of phase with the fireworks and occurs about 6 seconds early     The booms follow the flashes you see by about 3 seconds.     The music is out of phase with the fireworks and occurs about 3 seconds late.     The music has the wrong pitch with its frequency changed by the time it takes to reach  you.     The booms are so loud they occur at the same time as the flash of fireworks explosion.

If a machine produces sound with an intensity level of 97.1 dB, what would its intensity level have to be to reduce the intensity by a factor of 2.40?

An ultrasound unit is being used to measure a patient’s heartbeat by combining the emitted 2.0 MHz signal with the sound waves reflected from the moving tissue of one point on the heart. The beat frequency between the two signals has a maximum value of 520 Hz. What is the maximum speed of the heart tissue?

A pin with a mass of 0.15 g falls from rest on a table 1.0 m high. Upon reaching the floor, 0.02% of the kinetic energy of the pin is converted into a sound pulse lasting 0.10 s which is emitted in all directions. If the background noise intensity is 1.0x10-8W/m2 , how far can a person be to hear the noise of a pin drop?a)7.5mb)5.3mc)6.2md)1.4me)4.8mf)3.1mg)4.0mh)2.5m

A source of sound changes, so that it outputs half of its original power.  If the distance between you and the source didn't change, by what factor does the sound intensity you experience change?

In echolocation, a RADAR used infrared to determine the distance of a far away object. Estimate this range if the sender has received the reflected signal after 5.0 µs. 1.5 km 15 km 60 km 6.0 km