When a helicopter is hovering 1450 m directly overhead, an observer on the ground
measures a soundintensity I. Assume that sound is radiated uniformly from the helicopter and that ground reflections are negligible. How far must the helicopter fly in a straight line parallel to the ground before the observer measures a sound in
Twenty violins playing simultaneously with the same intensity combine to give an intensity level of 82.5 dB.
(a) What is the intensity level of each violin?
(b) If the number is increased to 40, will the combined intensity level be more than, less than, or equal to 165 dB? explain
A ten-year exposure to the sound of a riveting machine will cause your threshhold of hearing to shift from 0 dB to 30 dB. What is the soundintensity corresponding to 30 dB? The normal lowest detectable intensity is 1.0 X 10 -12 W/m squared.
Residents of Hawaii are warned of the approach of a tsunami by sirens mounted on the top of towers. Suppose a siren produces a sound that has an intensity level of 120 dB at a distance of 2.0 m. Treating the siren as a point source of sound, and ignoring reflections and absorption, find the intensity level heard by an observer
A typical adult ear has a surface area of about 1.9 10-3 m2. The soundintensity during a normal conversation is about 3.6 10-6 W/m2 at the listener's ear. Assume the sound strikes the surface of the ear perpendicularly. How much power is intercepted by the ear?
Pick a specific sound, give the decibels of the sound, and explain what this measurement means?
Example of the sound: Loud car horn on
Can you explain this to me?
(See attached file for full problem description)
Distance Costs Decibels
The general formula for the number of decibels corresponding to a change in soundintensity to relative to the former intensity is
Suppose that a sound has initial intensity measured in decibels. This sound now increases in intensi