Sound at 70 dB is 70 dB louder than the human reference level. That's 10⁷ times as much as the reference sound power.
Sound at 73 dB is 73 dB louder than the human reference level. That's 10⁷.³ or 2 x 10⁷ times as much as the reference sound power.
Sound at 80 dB is 80 dB louder than the human reference level. That's 10⁸ or 10 x 10⁷ times as much as the reference sound power.
Now we can adumup:
Intensity of all 3 sources = (10⁷) + (2 x 10⁷) + (10 x 10⁷)
Intensity = (13 x 10⁷) times the sound power reference intensity.
Intensity in dB = 10 log (13 x 10⁷) = 10 (7 + log(13)
Intensity = 70 + 10 log(13)
Intensity = 70 + 10 (1.114)
Intensity = 70 + 11.14
Intensity = <em>81.14 dB</em>
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Looking at the questioner's profile, I seriously wonder whether I'll ever get a comment in return from this creature, and how I'll ever find out if my solution is correct. For that matter, I'm also seriously questioning how and whether my solution will ever be used for anything.
Answer:
8.64 x 10^7 J
Explanation:
Intensity of sunlight, I = 1000 W/m^2
Length of panel, L = 6 m
Width of panel, W = 4 m
Area of the panel, A = L x W = 6 x 4 = 24 m^2
time, t = 1 hour = 3600 second
Energy = Intensity x area of panel x time
E = 1000 x 24 x 3600 = 8.64 x 10^7 J
Answer:
3.33 seconds
Explanation:
We can use the velocity formula [ v = u + at ] to solve.
Find the value "u".
135km/h -> 135km*1000m/3600s -> 37.5m/s
Find the value "v".
75km/h -> 75km*1000m/3600s -> 20.83m/s
Keep in mind we are dealing with "deceleration" so when we input 5.0m/s into the formula, it will be a negative value.
Now, find "t" which is the value we aren't given with the values we're given in the question.
20.83 = 37.5 - 5t
-16.67 = -5t
3.33 = t
Best of luck!
Answer:
The density is: 
Explanation:
Recall that density is defined as the quotient of the object's mass divided by volume. So, we calculate the volume of the 3 cm side cube:

then the density becomes:

Answer:
hide on a place where there is no windows take a radio
Explanation: