The picture is very blurry I wish I could help
There are an estimated 100 billion, so the answer would be D.) Billions
Answer:
Angle = 0.2520 radians
Explanation:
Complete question:
Sound with frequency 1220Hz leaves a room through a doorway with a width of 1.13m . At what minimum angle relative to the centerline perpendicular to the doorway will someone outside the room hear no sound? Use 344m/s for the speed of sound in air and assume that the source and listener are both far enough from the doorway for Fraunhofer diffraction to apply. You can ignore effects of reflections.
Given Data:
Speed of sound =v= 344 m/sec ;
Width of doorway =d= 1.13m ;
Frequency of sound =f= 1220 Hz ;
Solution:
As we know that
Wvelength = w = v/f = 344/1220 = 0.281967m
Now we also know that
w = dsin(A) where A is the angle
A = arcsin(w/d) =14.44° = 14.44*(3.14/180) = 0.2520 radians
At the angle of 0.252 radians relative to the centreline perpendicular to the doorway a person outside the room will hear no sound under given conditions.
Z - Gamma Rays
X - Visible Light
Gamma rays are heavily produced in the core of the sun but are diluted before they reach the surface (Z). And the surface is the only thing the human eye can see (X).
<h3>
Answer:</h3>
This is because the cloth soaked in water can absorb and evaporate the heat from your forehead.
<h3>
Explanation:</h3>
This technique is used to cool down your fever, and to help you feel better.
