Kamini's storeroom has only one electric bulb and she finds a little dark. She wants to fit an extra bulb. Her husband John suggests that he will instead fit more mirrors on the walls of the storeroom. Will John's idea work?

A Yes, though it will only feel brighter, the room will not actually become brighter.
B Yes, the mirrors will reflect light actually making the room brighter.
C No, without adding a light source, the room cannot be brightened.
D No, due to the reflections of the other objects, the room will become less bright.

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )