An air bubble originating from an under water diver has a radius of 5 mm at some depth h. when the bubble reaches the surface of the water, it has a radius of 6.6 mm. assuming the temperature of the air in the bubble remains constant, determine the absolute pressure at this depth h. the acceleration of gravity is 9.8 m/s 2 . answer in units of pa.

Absolute Pressure at depth h =

Explanation:

Given:

Assumptions:

According to Ideal Gas Law,

where,

For the given case, the temperature of the air bubble is constant. The number of molecules of the bubble also does not change, therefore,

PV = constant.

The pressure at the surface is equal to the atmospheric pressure,

The pressure at depth h is equal to sum of atmospheric pressure and the pressure of the water upto depth h,

Using these values,

The absolute temperature at that depth is given by

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