Answer:
Explanation:
wave length of light λ = 502 nm
screen distance D = 1.2 m
width of one fringe = 10.2 mm / 20
= .51 mm
fringe width = λ D / a , a is separation of slits
Puting the values given
.51 x 10⁻³ = 502 x 10⁻⁹ x 1.2 / a
a = 502 x 10⁻⁹ x 1.2 / .51 x 10⁻³
= 1181.17 x 10⁻⁶ m
1.18 x 10⁻³ m
= 1.18 mm .
Answer: Magnitude of the average force exerted on the glove by the other boxer is 827.86 N (approximately 828 N).
Explanation: Impulse is defined as the force acting on an object for a short period or interval of time.
Mathematically it is given by the relation:
Impulse = Force 
Time
According to the numerical values given in the question, I = 202 Ns and T = 0.244 s
So, Force F = 
= 
= 827.86 N
Magnitude of the average force exerted on the glove by the other boxer is 827.86 N (approximately 828 N).
Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P = 
where
f = focal length
Thus
f = 
f = 
= + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:
where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,
Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm
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.
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