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
Answer:
Sleeping, since your brain is working, but your physical body is not moving at all or moving rarely, therefore there is no work done in the activity of sleeping.
Explanation:
The correct answer is Option (C) distance and time
Explanation:
Average speed of any object is defined as the total distance that object travels over the time it takes to travel that distance. In other words, average speed is the total distance divided by the elapsed time.
Therefore, as you can see in the above equation, the two measurements that are essential for the calculation of the average speed are the (total) distance and the (elapsed) time.
Hence, the correct option is C.
Answer:
Distance = 70 meters
Explanation:
<u>Given the following data;</u>
Speed = 90 km/h
Time = 2.8 seconds
<u>Conversion:</u>
90 km/h to meters per seconds = 90 * 1000/3600 = 90000/3600 = 25 m/s
To find the distance covered during this inattentive period;
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the formula;
Making distance the subject of formula, we have;
Substituting into the above formula, we have;
<em>Distance = 70 meters</em>
Answer: 0.16Hz
Explanation:
Given that:
wavelength (λ) = 125 meters
speed (V) = 20 m/s
frequency (F) = ?
Recall that frequency is the number of cycles the wave complete in one second. And its value depends on the wavelength and speed of the wave.
So, apply the formula V = F λ
Make F the subject formula
F = V / λ
F = 20 m/s / 125 meters
F = 0.16 Hz
Thus, the frequency of the wave is 0.16 Hertz.
