You want to support a sheet of fireproof paper horizontally, using only a vertical upward beam of light spread uniformly over the sheet. There is no other light on this paper. The sheet measures 22.0 cm by 28.0 cm and has a mass of 1.50 g. 

(a) If the paper is black and hence absorbs all the light that hits it, what must be the intensity of the light beam?

(b) For the light in part (a), what are the amplitudes of its electric and magnetic fields?

(c) If the paper is white and hence reflects all the light that hits it, what intensity of light beam is needed to support it?

(d) To see if it is physically reasonable to expect to support a sheet of paper this way, calculate the intensity in a typical 0.500-mW laser beam that is 1.00 mm in diameter, and compare this value with your answer in part (a).