Answer:
#_photons = 30 photons / s
Explanation:
Let's start by finding the energy of a photon of light, let's use the Planck relation
E = h f
the speed of light is related to wavelength and frequency
c = λ f
we substitute
E = h c /λ
E₀ = 6.63 10⁻³⁴ 3 10⁸/500 10⁻⁹
E₀ = 3.978 10⁻¹⁹ J
now let's use a direct proportion rule. If the energy of a photon is Eo, how many fornes has an energy E = 1.2 10⁻¹⁷ J in a second
#_photons = 1 photon (E / Eo)
#_photons = 1 1.2 10⁻¹⁷ /3.978 10⁻¹⁹
#_photons = 3.0 10¹
#_photons = 30 photons / s
Heya!!
For calculate period, lets applicate formula:
<u>Δ Being Δ</u>
T = Period = ?
f = Frequency = 660 Hz
⇒ Let's replace according the formula:
⇒ Resolving
Result:
The period of that wave is <u>0,0015 seconds.</u>
<u>Δ IMPORTANT Δ</u>
The period is the INVERSE of the frequency. (T = 1 / f).
And the frequency is the inverse of the period (f = 1 / T)
Good Luck!!
b) 4m/s/s
This is because you divide the speed you reach, by the time it takes to get to that speed:
12m/s ÷ 3s = 4m/s/s
The units come from what you divide, meters per second ÷ seconds this can be written as m/s/s or ms-²