A train travels 20,000km in 500h. What is the average speed of the train?

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.

Which notation is used to represent an alpha particle? a. b. c. d.

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical