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Electric power is measured in watts (1 W = 1 J/s). About 95% of the power output of an incandescent bulb is converted to heat and 5% to light. If 10% of that light shines on your chemistry textbook, how many photons per second shine on the book from a 75-W bulb? (Assume that the photons have a wavelength of 550 nm.)

Respuesta :

10.376 x 10¹⁷ photon/s shine on the book from a 75-W bulb.

Calculation of  the energy of a single photon with a wavelength (λ) of 550 nm:

E = hc/λ

Where,

h = Planck's constant (6.626 x 10⁻³⁴ J·s)

c = speed of light (3x10⁸ m/s)

E = 6.626 x 10⁻³⁴ J·s x 3x10⁸ m/s ÷ (550x10⁻⁹m) = 3.614 x 10⁻¹⁹ J

1 proton = 3.614 x 10⁻¹⁹ J

1 J/s x 1 photon/3.614 x 10⁻¹⁹ J = 2.767 x [tex]10^{18}[/tex] photon/s = 1 W

Calculation of photons per second that shine:

A 75 W bulb converts 5% of its output into light

Therefore, 75 x 5/100 = 3.75 W

3.75 W is equal to [ 2.767x10¹⁸ photon/s x 3.75 ] = 10.376x10¹⁸ photon/s

Of those photons per second, 10% of that light shine on the chemistry textbook, thus:

10.376 x 10¹⁸ photon/s x 10/100 = 10.376 x 10¹⁷ photon/s

Hence,  10.376 x 10¹⁷ photon/s shine on the book from a 75-W bulb.

Learn more about photons here:

https://brainly.com/question/20912241

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