Answer:
Explanation:
Let the angle between the first polariser and the second polariser axis is θ.
By using of law of Malus
(a)
Let the intensity of light coming out from the first polariser is I'
.... (1)
Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.
By the law of Malus

So,



(b)
Now differentiate with respect to θ.


Infra-red has wavelengths just longer than visible light.
Answer:
1.15*10^-7 N/m²
Explanation:
Radiation pressure is the pressure exerted on any surface, as a result of the exchange of momentum between the object and its electromagnetic field.
The formula to calculate radiation pressure on a perfect absorber is
P = s/c, where
P = radiation pressure
s = intensity of light
c = speed of light
Now, on substituting the values and plugging it into the equation, we have
P = 34.5 / 3*10^8
P = 1.15*10^-7 N/m²
therefore, radiation pressure is found to be 1.15*10^-7 N/m²
1 Answer. 50% of the lunar surface is always illuminated by Sun