Achieve #4

[305572238]

A liquid is exposed to infrared radiation with a wavelength of 5.80×10−4 cm.
Assume that all the radiation is absorbed and converted to heat. How many photons are required for the liquid to absorb 24.96 J
of heat?

I’m confused about how to calculate the number of photons?

[Anthony Stone 1K]

The first step would be to convert your wavelength to meters. Next, you want to use that wavelength and plug it into c=lambda*v (frequency). Do this in order to find the frequency of this wavelength. You then want to use the frequency and plug it into E=hv to the total amount of energy in joules. After this divide 24.96 J of heat by your total energy and that is your number of photons. Hope this helps. Thats how I solved it.

[Shania Garrison Discussion 3E]

Hi! To calculated this i first used the E=(hc)/lambda equation to find the energy per photon. Make sure your units are in SI units before doing that. Second, I divided the amount of energy we want by the amount of energy per photon to get the amount of photons we would need.

[RossLechner3E]

The best place to start here would be to find the energy of each induvial photon at that wavelength using E=(hc)/(lambda), make sure to convert from cm to m as well. Then simply divide the desired amount of energy by the energy quantity for one photon and that will yield the number of photons required to absorb the desired amount of radiation.

[JasmineReyes-2K]

Hi!

You should first find the energy of each individual photon at their wavelength and find the total amount of energy in joules :)

[Raizel Ferrer 1H]

First, the given wavelength is in cm so you would have to convert it to meters. Then, to find the total energy needed per photon in Joules, you would need to use E = hc/(lamda) equation where you would simply plug in all the values. Then, divide the amount of energy in heat by the energy needed per photon to calculate the amount of photons.