(adsbygoogle = window.adsbygoogle || []).push({}); 1. The night-adapted eye can detect as few as several photons per second -- say five to be definite. Assuming that the pupil of the eye is 0.6 cm in diameter, from what distance would it be possible for the naked eye to detect a 60-W lightbulb?

2. I'm not sure which equation to use. In the section where the problem is from, I get teh follow equations (which don't help me)

E=pc, E=hf, h=6.63x10^-34, p=h/lamda

3. Not sure which formula to use

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# Photons - Trying to find distance

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