An orange light has a wavelength of 720 nanometers. Calculate the frequency.

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.

What is the work done by the electric force to move a 1 c charge from a to b?