Answer:

Explanation:
As we know that flux of magnetic field from the closed loop is given by
![\phi = BAcos30[tex]now by Faraday's law we know[tex]EMF = \frac{d\phi}{dt}](https://tex.z-dn.net/?f=%5Cphi%20%3D%20BAcos30%5Btex%5D%3C%2Fp%3E%3Cp%3Enow%20by%20Faraday%27s%20law%20we%20know%3C%2Fp%3E%3Cp%3E%5Btex%5DEMF%20%3D%20%5Cfrac%7Bd%5Cphi%7D%7Bdt%7D)
now we will have

now we have

EMF = 10 Volts



Answer:
4.6 m
Explanation:
First of all, we can find the frequency of the wave in the string with the formula:

where we have
L = 2.00 m is the length of the string
T = 160.00 N is the tension
is the mass linear density
Solving the equation,

The frequency of the wave in the string is transmitted into the tube, which oscillates resonating at same frequency.
The n=1 mode (fundamental frequency) of an open-open tube is given by

where
v = 343 m/s is the speed of sound
Using f = 37.3 Hz and re-arranging the equation, we find L, the length of the tube:

Question:
What is uniform rectilinear motion?
Answer:
Uniform rectilinear motion is when an object travels at a constant speed with zero acceleration.
Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as



now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as



now we know that



so now the distance from friend must be 47 cm