A monochromatic beam of light has a frequency

of 7.69 × 10^14 hertz. What is the energy of a

photon of this light?

(1) 2.59 × 10^−40 J (3) 5.10 × 10^−19 J

(2) 6.92 × 10^−31 J (4) 3.90 × 10^−7 J

Explanation:

The energy of a photon of light can be calculated from the following equation;

where his Planck's constant and is given by,

f is the frequency of the light and is given by

So therefore,

(3) 5.10x

Explanation:

If you already know the frequency, the energy of photon can be calculated by using the formula :

E=hf

where,

E= energy of photon

f= frequency of the photon in Hz=  7.69 × 10^14 hertz

h=Planck's constant = 6.63 × 10-34 J s

therefore, E= (6.63 × 10^-34 )*(7.69 × 10^14 )

E= 5.09x10^-19 J ≈ 5.10× 10^−19 J

∴The energy of a  photon of this light is 5.10× 10^−19 J

an energy transformation flow diagram is shown

where is it ?

truck y has a greater velocity than truck x.