Explanation:
Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.
The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.
However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.
1
The image mentioned is in the attachment
Answer: a) P = 2450 Pa;
b) P = 2940 Pa;
c) F = 4.9 N
Explanation:
a) Pressure is a force applied to a surface of an object or fluid per unit area.
The image shows a block applying pressure on the large side of the piston. The force applied is due to gravitation, so:
P = 
P = 
P = 
P = 2450 Pa
The pressure generated by the block is P = 2450 Pa.
b) A static liquid can also exert pressure and can be calculated as:
ρ.g.h
where
ρ is the density of the fluid
h is the depth of the fluid
g is acceleration of gravity
600.9.8.0.5
2940 Pa
The pressure in the fluid at 50 cm deep is 2940 Pa.
c) For the system to be in equilibrium both pressures, pressure on the left side and pressure on the right side, have to be the same:
= 
F = 
Adjusting the units, 
= 0.002 m².
F = 
F = 4.9 N
The force necessary to be equilibrium is F = 4.9 N.
Explanation:
m = kg. v=m/s. g=m/s^2. h= m
>>1/2mv^2=mgh
>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m
>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m>>kg m^2/s^2=kg m^2/s^2 the fraction 1/2 won't be able to make any changes to to the dimensional expression of energy i.e half of energy is still energy therefore you can neglect the number .
<u>>>kg m^2/s^2=kg m^2/s^2</u><u> </u>
<u>></u><u>></u><u>J</u>= J
