Melting ice - how many photons?

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SUMMARY

The discussion focuses on calculating the number of photons required to melt a 2 kg block of ice at 0 degrees Celsius into water at the same temperature, using the wavelength of 620 nm. The relevant equation is E=hc/lambda, where E represents energy, h is Planck's constant, and c is the speed of light. Participants emphasize the need to relate the energy of the absorbed photons to the heat required for melting ice, which is approximately 334 kJ/kg.

PREREQUISITES
  • Understanding of the equation E=hc/lambda
  • Knowledge of the latent heat of fusion for ice (334 kJ/kg)
  • Basic principles of thermodynamics
  • Familiarity with photon energy calculations
NEXT STEPS
  • Calculate the energy required to melt 2 kg of ice using the latent heat of fusion.
  • Determine the energy of a single photon at a wavelength of 620 nm using E=hc/lambda.
  • Divide the total energy required by the energy per photon to find the number of photons needed.
  • Research the relationship between photons and molecular transitions in phase changes.
USEFUL FOR

Students studying physics, particularly those focusing on thermodynamics and quantum mechanics, as well as educators looking for practical applications of photon energy concepts.

mss90
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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?
 
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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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