The correct answer for the question that is being presented above is this one:
Phi = BAsin(theta)
<span>1. Phi(i) = BA </span>
<span>2. Phi(f) = 0 </span>
3. EMF = N(phi(i)-phi(f))/deltat
Here are the follow-up questions:
<span>1. What is the total magnitude Phi_initial of the magnetic flux through the coil before it is rotated? </span>
<span>2. What is the magnitude Phi_final of the total magnetic flux through the coil after it is rotated? </span>
<span>3. What is the magnitude of the average emf induced in the coil?</span>
Answer:
Because the wavelengths of macroscopic objects are too short for them to be detectable.
Explanation:
Wavelength of an object is given by de Broglie wavelength as:

Where, 'h' is Planck's constant, 'm' is mass of object and 'v' is its velocity.
So, for macroscopic objects, the mass is very large compared to microscopic objects. As we can observe from the above formula, there is an inverse relationship between the mass and wavelength of the object.
So, for vary larger masses, the wavelength would be too short and one will find it undetectable. Therefore, we don't observe wave properties in macroscopic objects.
For a cylinder that has both ends open resonant frequency is given by the following formula:

Where n is the resonance node, v is the speed of sound in air and L is the length of a cylinder.
The fundamental frequency is simply the lowest resonant frequency.
We find it by plugging in n=1:

To find what harmonic has to be excited so that it resonates at f>20Hz we simply plug in f=20 Hz and find our n:

We can see that any resonant frequency is simply a multiple of a base frequency.
Let us find which harmonic resonates with the frequency 20 Hz:

Since n has to be an integer, final answer would be 323.