Melting ice - how many photons?

AI Thread Summary
To determine how many photons are needed to melt a 2kg block of ice at 0 degrees Celsius into water at the same temperature, one must first calculate the energy required using the formula for heat, Q = mL, where L is the latent heat of fusion for ice. The energy of each photon can be calculated using E = hc/lambda, with lambda given as 620 nm. By equating the total energy from the absorbed photons to the heat required to melt the ice, the number of photons can be found. Additionally, the average number of H2O molecules converted from ice to water per photon can be calculated by dividing the total number of molecules in 2kg of ice by the number of photons. This approach combines concepts from thermodynamics and quantum physics to solve the problem.
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Homework Statement


how many photons (lambda=620*10^-9) must be absorbed to melt 2kg block of ice at 0deg into water at 0deg? and on average, how many H2O molecules does one photon convert from the ice phase to water phase?

Homework Equations


E=hc/lambda

The Attempt at a Solution


I have no idea how to do this? Never done anything like it before!
Any hints?
 
Physics news on Phys.org
Recall your first semester physics where you learned how to find the heat required to melt ice. The energy of the photons absorbed by the ice can be considered as equivalent to the required heat.
 

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