A red laser pointer emits light at a wavelength of 635 nm. If the laser emits 7.5 × 10-4 J of energy per second in the form of visible radiation, how many photons per second are emitted from the laser?
a.4.2 × 10-16 photons/sec
b.2.4 × 1015 photons/sec
c.1.8 × 1036 photons/sec
d.2.7 × 1022 photons/sec
e.6.3 × 1017 photons/sec
2007-05-31 06:49:23 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Using the equation for energy of a photon of light, E = hf, or hc/lambda ... you find the energy emitted by 1 photon is 3.13 x 10^-19 J. Since there is an energy of 7.5 x 10^-4 J, you can use a proportion to find that the answer is B.
2007-05-31 07:03:06 · answer #1 · answered by The Chuck 3 · 1⤊ 0⤋
each and each photon has an ability of E = 2.02×10?¹? J. To get a complete ability of Etotal = 0.fifty two J you will need Etotal/E = 2.fifty 8×10¹? photons. because of the fact it takes 32 seconds to get 0.52J, you have 2.fifty 8×10¹?/32 = 8.07×10¹? photons in keeping with 2nd on elementary.
2016-12-30 09:03:58 · answer #2 · answered by lass 3 · 0⤊ 0⤋
given 7.5 * 10^-4 J/s total energy per unit second
energy per photon = h*f = h*c/wavelength.
= 3.13 * 10^-19 per photon
photons per sec = 7.5*10^-4 / 3.13 * 10^-19
= 2.4 * 10^ 15 photons/s
the answer is b.
2007-05-31 06:59:10 · answer #3 · answered by lilmaninbigpants 3 · 0⤊ 1⤋
b.2.4 × 1015 photons/sec
2007-05-31 07:07:37 · answer #4 · answered by ag_iitkgp 7 · 0⤊ 1⤋