Bob can row 14 mph in still water. the total time to travel downstream and return upstream to the starting point is 4 hours. if the total distance downstream and back is 42 miles, determine the speed of the river (current speed).

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared