P. 4092. A laser emits light impulses of wavelength 580 nm and of energy 20 J, which last for 0.5 ms. This light is aimed perpendicularly at a sheet made of caesium, and is focused to a circle of diameter 12 mm. 90% of the light is absorbed and 10% is reflected.
a) How many photons hit the metal sheet during one impulse?
b) Find the pressure of light.
c) Find the maximum of the speed of the electrons which are ejected by the caesium sheet.
Deadline expired on 13 October 2008.