A beam of light polarized along the y axis and moving along the +z axis passes through two polarizing sheets with axes of polarization oriented 30° and 70° measured clockwise from the positive direction of the y axis. The final intensity of the beam is found to be 61 W/m². What is the initial beam intensity? (1) 280 W/m² (2) 700 W/m² (3) 200 W/m² (4) 50 W/m² (5) 140 W/m²

Optical tweezers use light from a laser to move single atoms and molecules around. Suppose the intensity of light from the tweezers is 1000 W/m², the same as the intensity of sunlight at the surface of the Earth. (a) What is the pressure on an atom if light from the tweezers is totally absorbed? Pa (b) If this pressure were exerted on a tritium atom, what would be its acceleration? (The mass of a tritium atom is 5.01 x 107 -27 kg. Assume the cross-sectional area of the laser beam is 6.65 x 10-2⁹ m².) m/s²

Assume the mostly infrared radiation from a heat lamp acts like a continuous wave with wavelength 1.50 µm. (a) If the lamp's 205 W output is focused on a person's shoulder, over a circular area 24.0 cm in diameter, what is the intensity in W/m2? 2266.9 W/m2 (b) What is the peak electric field strength in kV/m? 0.924 X kV/m (c) Find the peak magnetic field strength in µT. 3.08 X µT (d) How long will it take in seconds to increase the temperature of the 3.80 kg shoulder by 2.00°C, assuming no other heat transfer and given specific heat is 3.47 x 103 J/(k • °C)? 128.64

An electromagnetic wave of frequency 3.2×1014 Hz falls on a medium of refractive index 4.1. The speed of E-M waves in vacuum is 3×108 m/s. The wavelength of the E-M wave in vacuum, λ0 =  Unit           . The speed of the E-M wave in the medium, v =  Unit           . The wavelength of the E-M wave in the medium, λ =  Unit           . If the incident wave falls from air and the angle of incidence is 17.5°, what is the angle of refraction? The angle of refraction, θr =  Unit

Initially unpolarized light is sent along the z-axis into a system of three polarizing sheets placed perpendicular to the z-axis and whose polarizing angles with respect to y-axis are 22º (first sheet), 89º (second sheet), and 56º (the last sheet). What percentage of the initial light intensity is transmitted by the system? Express your answer as a percentage, to at least one digit after the decimal.