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NARA [144]
3 years ago
14

The earplug can reduce the sound level to about 18 decibels (dB). What percentage reduction is this intensity?

Physics
2 answers:
zlopas [31]3 years ago
8 0

Answer:

1 x 10 -10 whisper at 1m distance.

Explanation:

  • Properly fitted ear plugs an reduce noise form 15-30db. Although they are better for low frequency
marishachu [46]3 years ago
8 0

Answer:

The change in intensity is 63%.

Explanation:

intensity level = 18 db

Let the intensity is I.

Io = 10^(-12) W/m^2

Use the formula of intensity

dB = 10 log\left ( \frac{I}{Io} \right )\\\\18 = 10 log\left ( \frac{I}{Io} \right )\\\\1.8 = log\left ( \frac{I}{Io} \right )\\\\\left ( \frac{I}{Io} \right )=63.1

So, the change in intensity is 63%.

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A circuit in a radio receiver requires a current of at least 1.0 microamp in order to detect a signal. How many electrons pass t
Paladinen [302]

Answer:

The number of electrons passes through the circuit if it detects a signal which persists for 1.0 microseconds is 6.25\times 10^{6}.

Explanation:

A circuit in a radio receiver requires a current of at least 1.0 microamp in order to detect a signal. It is required to find the number of electrons passing through the circuit if it detects a signal which persists for 1.0 microseconds.

It is known that the total amount of charge passing through a circuit is calculated as, Q=It.

Where I is the amount of current passing through a time of t.

For this problem, I=1.0 microamp, and t=1.0 microseconds. Therefore the amount of charge is,

$$\begin{aligned}Q&=I\times t\\&=1.0\text{ }\mu\text{A}\times 1.0\text{ }\mu\text{s}\\&=1.0\times 10^{-6}\text{ }\mu\text{A}\times 1.0\times 10^{-6}\text{ }\mu\text{s}\\&=10^{-12} \text{ C}\end{aligned}$$

The amount of charge in one electron is e=1.6\times 10^{-19} \times{ C}, therefore the number of electrons passing through the circuit while carrying 10^{-12} \text{ C} amount of charge is,

$$\begin{aligned}n&=\frac{Q}{e}\\&=\frac{10^{-12} \text{ C}}{1.6\times 10^{-19} \times{ C}}\\&=6.25\times 10^{6}\end{aligned}$$

To know more about the number of electrons passing through the circuit, refer to:

brainly.com/question/13199730

#SPJ4

6 0
1 year ago
If block D weighs 300 lb and block B weighs 275 lb determine the required weight of block C and the angle theta for equilibrium?
adoni [48]
Set up a free body diagram. 

<span>and by reason, Tcd = Tbd </span>

<span>Tbd y = 275 - 300*sinθ </span>
<span>Tcd y = Tc - 300*sin30 </span>

<span>Tbd x = 300*cosθ </span>
<span>Tcdx = 300 * cos30 </span>

<span>Tbd^2 = (275 - 300*sinθ)^2 + (300*cosθ)^2 </span>
<span>Tcd^2 = (300*sin30)^2 + (300 * cos30)^2 </span>

<span>(275 - 300*sinθ)^2 + (300*cosθ)^2 = (300*sin30)^2 + (300 * cos30)^2 </span>
<span>etc.</span>
5 0
3 years ago
X-component of length 5 and a y-component of length 4. What is the angle of the vector?
yKpoI14uk [10]
The direction of the vector with respect to the x-axis
is the angle whose tangent is      (4/5) .

             Arctan(4/5) = 38.7°  counterclockwise from the x-axis.
4 0
3 years ago
Of the 5000 species of mammals, 250 species are carnivorous. What is the ratio of carnivorous to mammals?
Mekhanik [1.2K]

Answer: The ratio of carnivorous species to all mammal species is 1:20

Explanation:

250:5000 = 250/250 = 1

250:5000 = 5000/250 = 20

Answer = 1:20

4 0
2 years ago
When an athlete holds the barbell directly over his head, the force he exerts on the barbell is the same as the force exerted by
frutty [35]

Answer:

Explained

Explanation:

When the barbell is accelerated upward, the force exerted by the athlete is greater than the weight of the barbell. (The barbell, simultaneously, pushes with greater force against the athlete.) When acceleration is downward, the force supplied by the athlete is less than the force applied by the barbell on the athlete.

5 0
3 years ago
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