Multiple shadow regions can be observed in the wall behind the keyhole of a door. Option B is correct.
<h3>
What is diffraction?</h3>
It is a phenomenon that happens when a wave (Light) is passed through a narrow aperture or a sharp edge, the light bends at the edges.
The light bends at the edges because the sharp edges have less diameter than the wavelength of light.
Therefore, multiple shadow regions can be observed in the wall behind the keyhole of a door.
Learn more about diffraction:
brainly.com/question/10303995
Answer:
2.7 J
Explanation:
The energy of one photon is given by
where
h is the Planck constant
f is the frequency
For the photons in this problem,
So the energy of one photon is
The number of photons contained in 1.0 mol is
(Avogadro number)
So the total energy of 
photons contained in 1.0 mol is
Sorry im from the UK, ill do my math in metric :)
5) work done = force * distance moved in direction of force
170J = 140N* ?d
170J/140N = 1.21m
F=Ma
140N/9.81ms^-2=
14.27Kg or 31.46Ib
you could do the fast alternative simplified route to this question
as 140/4.45 = 31.46Ib
it cant beacuse its not a person
