A barking dog delivers about 1.0 mW of power, which is assumed to be uniformly distributed in all directions. What is the intensity level in decibels at a distance 5.00 m from the dog? The threshold of human hearing is 1.0 × 10-12 W/m2
A) 61 dB
B) 63 dB
C) 65 dB
D) 68 dB
C
You might also like to view...
A 0.5 kg fish, hooked as shown below, starts to swim away at a speed of 3 m/s. The angular momentum of the fish relative to the hand holding the fishing rod is about
a.
To "spear" a blue fish with a red laser beam and compensate for refraction, aim your laser
A) directly at the sighted fish. B) above the sighted fish. C) below the sighted fish.
On a particular day, the air temperature is 75°F. If lowering the air temperature by 9° would cause the air to be saturated, what is the relative humidity?
An oil film floats on a water surface. The indices of refraction for water and oil, respectively, are 1.333 and 1.466 . If a ray of light is incident on the air-to-oil surface at an angle of 41.9° with the normal, what is the incident angle at the oil-to-water surface?
a. 30.1° b. 27.1° c. 37.4° d. 41.9° e. 33.5°