Kate gathered three boxes of the same size made of different materials: glass, clear plastic, and aluminum painted black. she placed them on a window sill i0n the sun for an hour and then measured the warmth of the air in each box. in this experiment, the types of box materials are a(n)

a. independent variable.

b. constant

c. control

d. dependent variable

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.

Diamond will scratch quartz. true or false

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?