Homework #5

[206190205]

How many photons with a wavelength of 815 nm are needed to melt 471g of ice? The enthalpy of fusion of water can be found in the table.

Number of photons:
After finding how much energy it takes per photon, I know that I have to divide that by the total amount of energy, but my answer is off. Does it matter when you round the numbers when calculating?

[Evonne Xu 3I]

Assuming the calculations you've done are correct, you should be dividing the total amount of energy it takes to melt the ice by the energy of a single photon instead of the other way around. I've found that the rounding generally doesn't matter too much as long as it is close to the answer.

[Harleen Kaur]

Hello,

No as long as you have the numbers right rounding to the decimal does not make a difference especially since the final is mutiple choice so you can see which one is the answer as long as you are close enough.