The index of refraction of glass is 1.52 and that of water is 1.333 . part a: compare the speed of light in water with the speed of light in glass. part b: with respect to the normal, compare the angle of refraction in water with the angle of refraction in glass. assume refraction is of a light ray entering from the air.

A) speed of ligth in water=2.25*10^8 m/s

while the speed of ligth in glass =1.97*10^8 m/s

B) sin(θr)=0.75*sin(θi) ( water)

sin(θr)=0.66*sin(θi) ( glass)  

Then sin (θrwater)/(sin (θrglass)=1.14

Explanation: In order to explain this problem we have to consider the expression for speed of light in differents materials, which is given by:

v=c/n where c is the speed of ligth in vacuum and n is the refractive index of the material.

vwater=3*10^8/1.333=2.25*10^8 m/s

vglass=3*10^8/1.53=1.97*10^8 m/s

On the othet hand to calculate the refraction angles in water and glass for the light entering from air we have to take into account the second Snell law which is:

nair*sin (θi)=nwater*sin (θr)

sin (θrwater)= nair/nwater* sin(θi)=0.75*sin (θi)

for the glass

nair*sin (θi)=nglass*sin (θr)

sin (θrglass)= nair/nglass* sin(θi)=0.66*sin (θi)

dividing both we have

sin (θrwater)/(sin (θrglass))=0.75/0.66=1.14

The refraction angle in water is higher than the obtained for the glass.

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