posted by jimmercarbone .
A microwave oven heats by radiating food with microwave radiation which is absorbed by the food and converted to heat. Suppose an oven's radiation wavelength is 12.5 cm. A container with 0.250 liter of water was placed in the oven and the temperature of the water rose from 20 degrees celsium to 100 degrees celsium. How many photons of this microwave radiation were required. Assume that all energy from the radiation were used to raise the temperature of the water
E per photon = hc/wavelength
Convert 12.5 cm to m and solve for E.
(note: 12.5 cm = 0.125m)
How much total energy did the water absorb. That's mass H2O x specific heat H2O x (Tfinal-Tinitial).
Eper photon x # photons = total E H2O.
Solve for # photons.