You have a Coke bottle with an air cavity that is 0.220 m deep. You add water to
the bottle, shortening the column, so
that when you blow across the top, it
plays a 528 Hz fundamental. How tall is
the water column in the bottle?

0.0576

Explanation:

The equation for fundamental frequency for closed pipes is as follows:

f(1) = v/4L

In which v is the speed of sound (343 m/s) and L is the length of the pipe. Therefore:

528 = 343/4L

x = 0.1624

This is not the answer as you still need to subtract it from the original length.

0.220 - 0.1624 = 0.0576

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

a sonic boom is a loud boom that breaks the sound barrier

explanation: