An alarm clock is ringing inside a jar. You are able to pump air out with a vacuum pump. What happens as more and more air is removed? a) The intensity of the sound from the bell does not change. b) The speed of the sound from the bell gradually increases. C) The frequency of the sound from the bell gradually increases. d) The sound intensity from the bell gradually decreases. e) The frequency of the sound from the bell gradually decreases.

Imagine a ringing bell set inside a sealed glass jar. Once all the air is removed and a vacuum is created, the ringing sound is no longer heard. Explain why this happens.   The glass prevents any sound from escaping.   The pressure of the outside air causes the sound to remain within the jar.   The lack of air in the jar causes the ringing to stop.   Without air, the sound waves cannot travel to the ear.

1. Like most dolphins, "Sparky the Wonder Dolphin" uses echolocation (or sonar) by emitting high frequency "clicks" to locate objects in the water around her. Typical frequency of a dolphin's sonar click is 100 kHz, while the typical intensity of a sonar click at a distance of 1 m from a dolphin's head is 200 dB. The speed of sound in sea water is about 1520 m/s. If Sparky emits a sonar click that bounces off a school of tuna 20 km distant, a) how long must she wait to hear the reflected pulse, and b) what is the intensity in dB of the reflected pulse that she hears?

The speed of sound in air is 330 m s-¹ 1. A motorcyclist travelling at a speed of 29 m s-¹ sounds the horn on their motorbike while passing a pedestrian beside the road. The rider hears the horn as a sound of frequency 250 Hz. a. What frequency does the pedestrian hear: i. when the motorcycle approaches? ii. when the motorcycle moves away? b. Explain why, when the motorcycle is right in front, the pedestrian hears the same frequency as the rider. D

What is the dynamic range of human ear?a. threshold of hearing (W/m2)b. threshold of pain (W/m2)c. SIL of threshold of hearing(dB)d. SIL of threshold of pain(dB)e. Sound intensity level of 200 dB

Four emergency vehicles (AD) are driving near you, each with a siren emits sound at the same frequency. You are standing still, and information about each vehicle's motion is given below. Rank the vehicles by the frequency of sound you hear from each from lowest to highest.

An electric guitar's amplifier is at a distance of 5.00 m. a) Find the intensity of its sound waves when its power output is 0.25 W, and what is the sound level at this distance? b) Find the intensity of the sound waves when the amplifier's power output is 0.50 W, and what is the corresponding sound level?

8. When you are 5.00 meters from a point source of sound waves you detect an intensity level, B, of 117 dB. The power output of the source is: a. What is the intensity level, ß, that you will detect if you moved to a location that is 10.0 meters from the source? Note your answer should be in dB. b. What is the power output of the source (in Watts)?

49. What will most likely happen to a ringing bell if placed inside a bell jar connected to a vacuum pump? A. The sound intensity will increase.B. The sound intensity will decrease.C. Frequency of the sound will decrease.D. The speed of sound will increase.

A 4.50 m long rope is stretched between two supports with a tension that makes the speed of transverse waves 48.0 m/s . a)What is the wavelength of the fundamental tone? b)What is the frequency of the fundamental tone? c)What is the wavelength of the second overtone? d)What is the frequency of the second overtone? e)What is the wavelength of the fourth harmonic? f)What is the frequency of the fourth harmonic?