When monochromatic light shines perpendicularly on a soap film (n = 1.33) with air on each side, the second smallest nonzero fil
1 answer:
Let us start from considering monochromatic light as an incidence on the film of a thickness t whose material has an index of refraction n determined by their respective properties.
From this point of view part of the light will be reflated and the other will be transmitted to the thin film. That additional distance traveled by the ray that was reflected from the bottom will be twice the thickness of the thin film at the point where the light strikes. Therefore, this relation of phase differences and additional distance can be expressed mathematically as
We are given the second smallest nonzero thickness at which destructive interference occurs.
This corresponds to, m = 2, therefore
The index of refraction of soap is given, then
Combining the results of all steps we get
Rearranging, we find
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Answer:
Approximately , assuming that
.
Explanation:
Let and
denote the mass and acceleration of Spiderman, respectively.
There are two forces on Spiderman:
- Downward gravitational attraction from the earth:
.
- Upward tension force from the strand of web
.
The directions of these two forces are exactly opposite of one another. Besides, because Spiderman is accelerating upwards, the magnitude of (which points upwards) should be greater than that of
(which points downwards towards the ground.)
Subtract the smaller force from the larger one to find the net force on Spiderman:
.
On the other hand, apply Newton's Second Law of motion to find the value of the net force on Spiderman:
.
Combine these two equations to get:
.
Therefore:
.
By Newton's Third Law of motion, Spiderman would exert a force of the same size on the strand of web. Hence, the size of the force in the strand of the web should be approximately (downwards.)