A 650 lines/mm diffraction grating is in an empty aquarium tank. The index of refraction of the glass walls is nglass = 1.50. A helium-neon laser (λ = 633nm) is outside the aquarium. The laser beam passes through the glass wall and illuminates the diffraction grating. What is the first-order diffraction angle of the laser beam? What is the first-order diffraction angle of the laser beam after the aquarium is filled with water.

The intensity of a polarized electromagnetic wave is 12 w/m^2. part a) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=0∘ with the plane of polarization? part b) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=30∘ with the plane of polarization? part c) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=45∘ with the plane of polarization? part d) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=60∘ with the plane of polarization? part e) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=90∘ with the plane of polarization?

In a system, when potential energy decreases, then entropy also decreases. true false

In what direction does an applied force move an object