Answer:
far from the speaker the intensity drops to 85 dB.
Explanation:
In the equation for the Decibel scale
The ratio of the intensities can be written as
And since
and
,
meaning
Putting this into equation (1), we get:
Now, if the intensity is 100 dB when the distance is 5 meters, we have:
by taking both sides to the exponent:
Now equation (2) becomes
when the intensity level is 85 dB we have
take both sides to exponents and we get:
Thus, far from the speaker the intensity drops to 85 dB.
Answer: 2561.7 pounds
Explanation:
If we assume the total weight of an airplane (in pounds units) as a <u>linear function</u> of the amount of fuel in its tank (in gallons) and we make a Weight vs amount of fuel graph, which resulting slope is 5.7, we can use the slope equation of the line:
(1)
Where:
is the slope of the line
is the airplane weight with 51 gallons of fuel in its tank (assuming we chose the Y axis for the airplane weight in the graph)
is the fuel in airplane's tank for a total weigth of 2390.7 pounds (assuming we chose the X axis for the a,ount of fuel in the tank in the graph)
This means we already have one point of the graph, which coordinate is:
Rewritting (1):
(2)
As Y is a function of X:
(3)
Substituting the known values:
(4)
(5)
(6)
Now, evaluating this function when X=81 (talking about the 81 gallons of fuel in the tank):
(7)
(8) This means the weight of the plane when it has 81 gallons of fuel in its tank is 2561.7 pounds.
Answer:
434.0 V/m
Explanation:
The power output of the laser is:
while the radius of the beam is
so the cross-sectional area is
So the intensity of the laser beam is
The intensity of a laser beam is related to the magnitude of the electric field by
where
c is the speed of light
is the vacuum permittivity
Solving the formula for E, we find
I think it would be from the box to greg
Answer:
Solution
Verified by Toppr
Correct option is
C
3 cm
RI=apparent depthreal depth
Substituting, 34=apparentdepth12
Therefore, apparent depth=412×3=9
The height by which it appears to be raised is 12−9=3cm
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SIMILAR QUESTIONS
A coin is placed at the bottom of a glass tumbler and then water is added. It appeared that the depth of the coin has been reduced because
Medium
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A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 9.4 cm. What is the refractive index of water? If water is replaced by a liquid of refractive index 1.63 up to the same height, by what distance would the microscope have to be moved to focus on the needle again?