Hi! I was able to find the energy per photon, however, I am having trouble converting it to watts. Can someone please explain how I'm supposed to do it, I'd greatly appreciate it!!
1.3 In each second, a certain lamp produces 2.4 3 1021 photons with a wavelength of 633 nm. How much power (in watts) is produced as radiation at this wavelength (1W 5 1 J?s21)?
Focus 1 Exercise 3
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Re: Focus 1 Exercise 3
Postby Giselle Granda 3F » Sun Nov 01, 2020 11:20 pm
The conversion for watts to joules is 1 W= 1 J/s. Therefore if say you had 32 W, that would equal to 32 J/s. Hope this helps!
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Re: Focus 1 Exercise 3
Postby Jeffrey Hablewitz 2I » Sun Nov 01, 2020 11:23 pm
The way I solved it is :
I calculated the energy per photon (3.13 * 10^-19 joules) and multiplied this value by the number of photons produced per second (2.4 * 10^21). This gave me the amount of energy in joules per second (751 J/sec). Because 1joule/sec = 1 watt, the answer is 751 watts. This is rounded to 750 because there are two sig figs in the problem. The book provides the answer as 750 J, which is numerically correct but has the wrong units (the problem asked that the answer be given in watts).
I calculated the energy per photon (3.13 * 10^-19 joules) and multiplied this value by the number of photons produced per second (2.4 * 10^21). This gave me the amount of energy in joules per second (751 J/sec). Because 1joule/sec = 1 watt, the answer is 751 watts. This is rounded to 750 because there are two sig figs in the problem. The book provides the answer as 750 J, which is numerically correct but has the wrong units (the problem asked that the answer be given in watts).
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