Waves

Question 1

SHM explain

Answer 1

a = -ω^2 x

mention restorative force towards equlibrium

Question 2

Give 3 examples of forms of interference

Answer 2

1. If the resulting wave is larger than the component waves, the interference is “ Constructive”
2. If the resulting wave is smaller than the component waves, the interference is “ destructive”
3. If the wave has zero amplitude, the interference is “totally destructive”

Question 3

Difference between diffraction grating and two slit interference and why?

Answer 3

1. Peaks much brighter because: more sources
2. Peaks all have equal intensity because: every peak is the middle of a set
3. peaks are narrower because: destructive interference becomes more likely

Question 4

What does the principle of superposition predict

Answer 4

It predicts the resultant wave of interference

Question 5

What are rays and wavefronts

Answer 5

1. A ray is a line showing the path/direction of a wave
2. A wavefront is a line connecting all the points of the medium that are transmitting the same signal at the same time. They move forward through space

Question 6

Explain Snells’s Law

Answer 6

When rays move between media, their speed changes. That causes the wave to “bend” –> REFRACTION. This can be put in an equation which is the Snells’ law. (n1/n2) = (sinθ2 / sinθ1) = (v2/v1)

Question 7

What’s an index of refraction?

Answer 7

n= c/v

c = speed of light in vacuum
v = speed of light in the particular medium

Question 8

What is Reflection

Answer 8

the change of direction of an incident ray when it meets a boundary. When the wave meets, it creates an angle of incidence to the normal, and when reflected, an angle of reflection appears. Note: The angle of incidence is equal to the angle of reflection

Question 9

Longitudinal waves is when the direction of the oscillations is _______ to the direction the wave travels

Answer 9

parallel

Question 10

How does a Standing wave happen

Answer 10

It happens when two waves with similar amplitude and frequency pass through each other in opposite directions. They involve a matter wave reflecting from a boundary and interfering with the incident waves as they pass through the medium.

Question 11

Waves ____ pass through openings smaller than themselves (than the wavelength), and once a wave has been created, its frequency _____ change, it’s like the wave’s DNA.

Answer 11

cannot

Question 12

refraction is…

Answer 12

when a light wave makes an angle of incidence with a boundary that is not perpendicular to it, and the direction of the wave changes as it enters this second medium.