## HW Question Focus 1, 1.3

Nikki Razal 1L
Posts: 95
Joined: Fri Aug 30, 2019 12:17 am
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### HW Question Focus 1, 1.3

How would you solve the problem Focus 1.3 in the textbook:
"In each second, a certain lamp produces 2.4 x 10^21 photons with a wavelength of 633 nm. How much power (in watts) is produced as radiation at this wavelength (1W = 1 J x s^-1)?"
I tried using E=hv and c=wavelength(frequency) and I got the wrong answer

AnvitaaAnandkumar_1B
Posts: 56
Joined: Fri Aug 02, 2019 12:15 am

### Re: HW Question Focus 1, 1.3

I first calculated the energy released per photon - which you get by using E = hc/lambda = 3.14 x 10^(-21)
I then calculated the total energy released in a second by multiplying the energy per photon (which I found) with the number of photons produced. I got this value to be 7.536 J.
Since the question gives us the number of photons released per second, our calculation gives us the energy released per second. And energy per second is power
Therefore, The power in one second is 7.536 J/s.