Question

Enormous numbers of microwave photons are needed to warm macroscopic samples of matter. A portion of soup containing 225 g water is heated in a microwave oven from 23°C to 91°C, with radiation of wavelength 1.55 10-2 m. How many photons are absorbed by the water in the soup?

Answer 1

E = mass water x specific heat water x (Tfinal-Tinitial).
E = 225 x 4.184 x (91-23) = ?? Joules needed.

E = hc/wavelength = ??joules from one photon.
So how many photons are required?

Answer 2

8.6*10^-19