A flow of electricity that constantly reverses direction. In the United States it reverses itself 120 times per second.
1 answer:
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Answer:
b. AG, work function=4.74eV
Explanation:
Ultraviolet light starts at the end of the visible light spectrum, where violet light ends:
(wavelength of lowest-energy ultraviolet light)
So, the lowest energy of ultraviolet light can be found by using the formula
where
h is the Planck constant
c is the speed of light
Substituting,
And keeping in mind that
This energy converted into electronvolts is
The work function of a metal is the minimum energy needed to extract a photoelectron from the surface of the metal. Therefore, the metals that exhibit photoelectric effect are the ones whose work function is larger than the energy we found previously, so:
b. AG, work function=4.74eV
Because for all the other metals, visible light will be enough to extract photoelectrons.
We can solve the problem by using Snell's law:
where
is the refractive index of the first medium (in this case, air, so 
)
is the refractive index of the second medium (in this case, water, so 
)
is the angle of incidence of the light, with respect to the vertical, so 
is the angle of refraction of the light inside the water, with respect to the vertical
Re-arranging the equation and using the data of the problem, we can find the the angle of refraction of the light inside the water:
where
Re-arranging the equation and using the data of the problem, we can find the the angle of refraction of the light inside the water: