Suppose a piano tuner hears 3 beats per sec-
1 answer:
Answer: 3 The string should be loosened because the frequency of the string is 5 Hz above the correct frequency.
Explanation: In order to explain this problem we have to consider the relationship bewteen the Tension and the frequency, this is given by:
We know that:
where μ and T are the mass linear density and Tension of teh string, respectively.
We also know that v=λ*ν the speed is related to the wavelength (λ) and the frequency (ν).
Then we have that frequency depents directely of the Tension (T) on the string.
In our case the frequency to be tuned is 3 Hz, firstly the piano tuner slightly tightening then he hears 5 beats per second (5 Hz). Then it is neccesary loose the tension on the string because the actual frequency is above to the correct frequency (3 Hz).
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Answer:
The potential difference between the plates is
Explanation:
Given that,
Distance = 1.4 mm
Electric field strength
Let the potential difference is V.
We need to calculate the potential difference between the plates
Using formula of electric field
Where, V = potential
d = distance
Put the value into the formula
Hence, The potential difference between the plates is
Answer:
distance is 13 m for 100 dB
distance is 409 km for 10 dB
Explanation:
Given data
distance r = 2.30 m
source β = 115 dB
to find out
distance at sound level 100 dB and 10 dB
solution
first we calculate here power and intensity and with this power and intensity we will find distance
we know sound level β = 10 log(I/) ......................a
put here value (I/) = 10^−12 W/m² and β = 115
115 = 10 log(I/10^−12)
so
I = 0.316228 W/m²
and we know power = intensity × 4π r² ...............b
power = 0.316228 × 4π (2.30)²
power = 21.021604 W
we know at 100 dB intensity is 0.01 W/m²
so by equation b
power = intensity × 4π r²
21.021604 = 0.01 × 4π r²
so by solving r
r = 12.933855 m = 13 m
distance is 13 m
and
at 10 dB intensity is 1 × 10^–11 W/m²
so by equation b
power = intensity × 4π r²
21.021604 = 1 × 10^–11 × 4π r²
by solving r we get
r = 409004.412465 m = 409 km