Four resistors , R1=12ohms, R2= 15 ohms , R3= 18 ohms and R4=10 ohms are connected to 6 v battery in series what is the total resistance in the circuit?

What is the magnitude of the resultant vector round your answer to the nearest tenth

Two polarizers are oriented at 40∘ to each other and plane-polarized light is incident on them. if only 16 percent of the light gets through both of them, what was the initial polarization direction of the incident light?

Light traveling in water, nwater = 1.33, strikes a plastic block at an angle of incidence of 51.4°; part of the beam is reflected and part is refracted. if the index of refraction of the plastic is 2.0, what is the angle made by the reflected and refracted beams?