1. The problem statement, all variables and given/known data What is the algebraic expression for the number N of photons that must be absorbed to cause the indicated increase in temperature? Express your answer in terms of the wavelength λ, the specific heat capacity csh, the mass m of the glass plate, the increase in temperature Tdiff, Planck's constant h, and the speed c of light. 2. Relevant equations Q = cm&t (& = delta) E = hf f = c/λ photon energy = hc/λ 3. The attempt at a solution Putting them all together yields: h*(c/λ) --------- csh * Tdiff But that's incorrect. If Q is energy (E) then hf = cm&t. Then c/λ is subbed for f. Am I missing a piece of the formulaic puzzle here?