Waves in two dimensions
0/3
Intros
Lessons
0/5
Examples
Lessons
- A train of water waves reflected at a boundary. The angle between the incident ray and normal in 30°. What would be the angle between normal and reflected wave?
- Sound wave are reaching a rigid boundary at a speed of 330 m/s. What would be the speed of the reflected wave bouncing of the same medium?
- Refraction of water waves occurred from deep to shallow water. Explain what happens to the wavelength, speed and the frequency of the refracted wave.
- Light waves reflect off a boundary with frequency of 30Hz. The angle between the reflected wave and incident wave is given to be 60°. What are the values for angle of reflection and angle of incident?
- What is the difference between the diffraction of light waves through small gaps and large gaps?
Free to Join!
StudyPug is a learning help platform covering math and science from grade 4 all the way to second year university. Our video tutorials, unlimited practice problems, and step-by-step explanations provide you or your child with all the help you need to master concepts. On top of that, it's fun — with achievements, customizable avatars, and awards to keep you motivated.
Easily See Your Progress
We track the progress you've made on a topic so you know what you've done. From the course view you can easily see what topics have what and the progress you've made on them. Fill the rings to completely master that section or mouse over the icon to see more details.Make Use of Our Learning Aids
Earn Achievements as You Learn
Make the most of your time as you use StudyPug to help you achieve your goals. Earn fun little badges the more you watch, practice, and use our service.Create and Customize Your Avatar
Play with our fun little avatar builder to create and customize your own avatar on StudyPug. Choose your face, eye colour, hair colour and style, and background. Unlock more options the more you use StudyPug.
Topic Notes
In this lesson, we will learn:
- Reflection of two-dimensional waves
- Recreation of two-dimensional waves
- Diffraction of two-dimensional waves
Notes:
- Waves moving along rope or spring are mechanical waves that move only in one dimension.
- Waves on the surface of water or sound waves move in two dimensions.
- Similar to one one-dimensional waves, two-dimensional waves get both reflected and refracted.
- As waves from one medium to another, partially reflect and partially refract.
- Properties of two-dimensional waves can be shown using a ripple tank which contains a thin layer of water. Vibrating boards produce wave pulses with constant frequency. The lamp above the tank produces shadows below the tank to show the exact location of crest and troughs.
- Pulses travelling towards a rigid barrier get “Reflected”.
- Pulses reaching a boundary might change direction or get “Refracted”.
- Pulses passing through a small hole, spread or get “Diffracted”.
- A ray diagram model is used to study the reflection of two-dimensional waves.
- A ray is a line drawn at right angles to the crests of the waves.
Key terms using a ray model to study reflection:
Incident Ray: An arrow pointing towards the boundary
Point of incidence: Point where incident ray meets the boundary
Reflected Ray: An arrow pointing away from the boundary
A straight line: showing the direction of the barrier
Normal: A line drawn perpendicularly to the barrier at point of incidence
Angle on incidence (<i ): The angle between incident ray and NORMAL
Angle of reflection (<r ): The angle between reflected ray and NORMAL
Barrier
- According to the law of reflection; angle of incidence is equal to angle of reflection ( ∠θi=∠θr )
- Upon reflection Speed, Wavelength, and Frequency do NOT change.
Key terms using ray model to study refraction:
Incident Ray: An arrow pointing towards the boundary
Point of incidence: Point where incident ray meets the boundary
Refracted Ray: An arrow pointing away from the boundary in the other medium
A straight line: showing the direction of the barrier
Normal: A line drawn perpendicularly to the barrier at point of incidence
Angle on incidence (∠θi): The angle between incident ray and NORMAL
Angle of refraction (∠θr): The angle between refracted ray and NORMAL
- As waves move from one medium to another with different densities (shallow or deep), they get refracted, change direction at the boundary.
- Shallow medium: Lower Velocity, Shorter Wavelength, Same Frequency
- Deep medium: Higher Velocity, Longer Wavelength, Same Frequency
- The process of diffraction is the spreading of waves through a small gap, waves circulating out of the gap.
- Size of the gap affects the shape of the diffracted wave;
Interference of diffracted waves
- Diffracted waves interfere with each other producing constructive and destructive interface.
- The result of light interference through small gaps can be collected on a screen, light and dark fringes are seen on the screen. Points where waves interference constructively
2
videos
remaining today
remaining today
5
practice questions
remaining today
remaining today