1. A burglar coughs with an intensity of 2.3510^-7 W/m². The burglar alarm is sensitive to an intensity of 1.0 10^-10 W/m² and will ring if the detected sound is 30 dB greater than its detection threshold. Will the burglar's cough be detected?

1. The density of a string is doubled and it's tension is tripled. If the original frequency of the string was 125 Hz, what is the new frequency?

1. The speed of sound in water is approximately 1496 m/s. Theoretically, how hot would air need to be to have the same speed of sound as water?

1. The sixth harmonic of a 65 cm guitar string is heard. If the speed of sound in the string is 206 m/s, what is the frequency of the standing wave?

1. A source passing a stationary observer is emitting a frequency of 560 Hz. If the speed of sound is 95 km/h, what must the speed of the source be if the frequency source is 480 Hz?

1. The two waveforms below have the same amplitude but slightly different frequencies. They are in the same medium at the same time, and they are interfering with each other. Draw the resulting beats. Use the principle of superposition, and mark the points of constructive interference and destructive interference.