Question

Calculate the energy of 100 photons if the wavelength of the light is 2000 a

Answer 1

Answer:

Explanation:

=> Here, lets calculate frequency first to find out the energy of photons.

f = C / λ

Where,

f = frequency

C = speed of light = 3 * 10⁻⁸ m/s

λ = wavelength of light = 2000°A = 2000 * 10⁻¹⁰ m

∴ f = 3 * 10⁻⁸ m/s / 2000 * 10⁻¹⁰ m

= 1.5 * 10¹⁵ sec⁻¹

Now, energy of photon, E:

E = h * f

= 6.63 ∗ 10⁻³⁴ J.s * 1.5 * 10¹⁵ s⁻¹

= 9.94 * 10⁻¹⁹ J

=> Thus, Energy of 100 photons:

= E * 100

=  9.94 * 10⁻¹⁹ J* 10²

= 9.94 * 10⁻¹⁷ J

Hence, the energy of 100 photons is 9.94 * 10⁻¹⁷ Joule.