A 100-watt light bulb radiates energy at a rate of 100 J/s. (The watt, a unit of power or energy over time, is defined as 1 J/s.) If all of the light emitted has a wavelength of 525nm, how many photons are emitted per second?

photons are emitted per second.

Explanation:

Let the number of photons emitted by bulb be 'n'.

Given:

Energy radiated by bulb per second (E) = 100 J

Wavelength of light emitted (λ) = 525 nm =

We know that,

Energy of a photon is given as:

Where,

Now, if there are 'n' photons, the energy will be equal to energy of 1 photon times the number of photons. So,

Now, rewriting in terms of 'n', we get:

Plug in the values given and solve for 'n'. This gives,

Therefore, photons are emitted per second.

this could be newton#'s law of cooling. the cooling curve is exponential