-- The reference level for sound wave intensity is the threshold of human hearing, defined as 10⁻¹² W/m² .
-- This question is talking about a 90dB sound. So its intensity is 10⁻³ W/m² .
-- The question tells us the size of the area that this sound is hitting. So the power absorbed by that area is ...
Power = (intensity) x (area)
Power = (10⁻³ W/m²) x (5 x 10⁻⁵ m²)
Power = (10⁻³ x 5 x 10⁻⁵) W
<em>Power = 5 x 10⁻⁸ Watts</em>
(That's 5 x 10⁻⁸ Joules of energy per second.)
Answer:
Inductance, L = 0.0215 Henry
Explanation:
Given that,
Capacitance of the capacitor, ![C=7.7\ nF=7.7\times 10^{-9}\ F](https://tex.z-dn.net/?f=C%3D7.7%5C%20nF%3D7.7%5Ctimes%2010%5E%7B-9%7D%5C%20F)
Potential difference, V = 12 V
The period of oscillation, ![t=8.1\times 10^{-5}\ s](https://tex.z-dn.net/?f=t%3D8.1%5Ctimes%2010%5E%7B-5%7D%5C%20s)
At resonance, the angular velocity is given by :
![\omega=\dfrac{1}{\sqrt{LC} }](https://tex.z-dn.net/?f=%5Comega%3D%5Cdfrac%7B1%7D%7B%5Csqrt%7BLC%7D%20%7D)
![\dfrac{2\pi}{t}=\dfrac{1}{\sqrt{LC} }](https://tex.z-dn.net/?f=%5Cdfrac%7B2%5Cpi%7D%7Bt%7D%3D%5Cdfrac%7B1%7D%7B%5Csqrt%7BLC%7D%20%7D)
![L=\dfrac{t^2}{4\pi^2C}](https://tex.z-dn.net/?f=L%3D%5Cdfrac%7Bt%5E2%7D%7B4%5Cpi%5E2C%7D)
![L=\dfrac{(8.1\times 10^{-5})^2}{4\pi^2\times 7.7\times 10^{-9}}](https://tex.z-dn.net/?f=L%3D%5Cdfrac%7B%288.1%5Ctimes%2010%5E%7B-5%7D%29%5E2%7D%7B4%5Cpi%5E2%5Ctimes%207.7%5Ctimes%2010%5E%7B-9%7D%7D)
L = 0.0215 Henry
So, the inductance of the coil is 0.0215 Henry. Hence, this is the required solution.
The angular speed of the lander must be 3.92 rpm
Explanation:
The (centripetal) acceleration of the lander is given by:
![a=\omega^2 r](https://tex.z-dn.net/?f=a%3D%5Comega%5E2%20r)
where
is the angular speed
r is the length of the arm
In this problem, we have
r = 7.75 m
(we are told that the acceleration of the lander must be the same as the acceleration due to gravity at the surface of Europa, which is
Therefore we can find the angular speed of the lander:
![\omega=\sqrt{\frac{a}{r}}=\sqrt{\frac{1.31}{7.75}}=0.411 rad/s](https://tex.z-dn.net/?f=%5Comega%3D%5Csqrt%7B%5Cfrac%7Ba%7D%7Br%7D%7D%3D%5Csqrt%7B%5Cfrac%7B1.31%7D%7B7.75%7D%7D%3D0.411%20rad%2Fs)
And keeping in mind that
![1 rev = 2\pi rad](https://tex.z-dn.net/?f=1%20rev%20%3D%202%5Cpi%20rad)
![1 min = 60 s](https://tex.z-dn.net/?f=1%20min%20%3D%2060%20s)
We can convert this angular speed into rpm:
![\omega = 0.411 rad/s \cdot \frac{60 s/min}{2\pi rad/rev}=3.92 rpm](https://tex.z-dn.net/?f=%5Comega%20%3D%200.411%20rad%2Fs%20%5Ccdot%20%5Cfrac%7B60%20s%2Fmin%7D%7B2%5Cpi%20rad%2Frev%7D%3D3.92%20rpm)
Learn more about rotational motion:
brainly.com/question/9575487
brainly.com/question/9329700
brainly.com/question/2506028
#LearnwithBrainly
Answer:
the function of the thrombocytes is to clott blood