Topic 3.1 - General Wave Properties Flashcards Preview

Physics > Topic 3.1 - General Wave Properties > Flashcards

Flashcards in Topic 3.1 - General Wave Properties Deck (31)
Loading flashcards...
1
Q

What is a wave?

A

A regular disturbance transferring energy in the direction of the wave’s propagation without transferring matter.

2
Q

What is a transverse wave?

A

A wave in which oscillations are at right angles (perpendicular) to the direction of motion.

3
Q

Give examples of transverse waves

A

Waves on a string, all electromagnetic waves (eg. visible light), ripples on water, vibrations on guitar strings

4
Q

What is a longitudinal wave?

A

A wave where the oscillations are parallel to (in the same direction as) the direction of motion.

5
Q

Give examples of longitudinal waves

A

Pulses along a spring, sound waves, ultrasound

6
Q

Transverse waveforms have…

A

Peaks and troughs

7
Q

Longitudinal waveforms have…

A

Compressions and rarefactions

8
Q

Wavelength is…

A

The wavleegth of a wave is the distance between succesive crests

9
Q

Frequency is…

A

The number of complete waves passing a given point per second, or the number of waves per second produced by the source.

10
Q

State the wave equation

A

v =λ x f

  • v = velocity (m/s)
  • λ = wavelength (m)
  • f = frequency (Hz)
11
Q

What is refraction?

A

Refraction is the change in speed of a wave when crossing a boundary between two media, resulting in a change in direction.

12
Q

Which property of a wave is not changed by refraction?

A

The frequency.

13
Q

What happens when waves are incident on a flat surface?

A

Reflection

14
Q

stronger reflected wave is produced when…

A

The surface is smoother

15
Q

Why do rough surfaces appear matt when illuminated?

A

The reflected light rays are scattered in all directions.

16
Q

When entering a denser material, light waves…

A

…slow down and bend towards the

normal.

17
Q

When entering a less dense material, light waves…

A

…speed up and bend away from the normal.

18
Q

What is diffraction?

A

The spreading out of waves passing through a narrow gap or across an edge.

19
Q

What size of gap produces the largest diffraction?

A

A gap of the same width as the wavelength of the wave passing through it.

20
Q

What is a ripple tank?

A

A shallow glass tank with an oscillating paddle/needle to create waves. It is illuminated from above so waves can be seen on the surface below the tank

21
Q

Describe how to demonstrate reflection using a ripple tank.

A

Waves will reflect off the glass sides of the tank.

22
Q

Describe how to demonstrate refraction using a ripple tank.

A

Place a glass box across half of the floor of the ripple tank. The waves will change speed when travelling through the less dense area.

23
Q

Describe how to demonstrate diffraction using a ripple tank.

A

Place two glass blocks in the middle of the tank, leaving a small gap, and observe the wave patterns.

24
Q

Transerve wave being sent along a rope

A
25
Q

What is the amplitude of a wave

A

The amplitude is defined as the maximum displacement (movement away) from the rest or undisturbed level.

26
Q

What are the three ways a wave’s direction of motion can change?

A
  • Refraction
  • Reflection
  • Diffraction
27
Q

How many ways can a wave change at a boundary?

A

3 times (refraction, reflection, diffraction)

28
Q

Diffraction with different gaps

A
  • If the gap size is very large relative to the size of the wavelength, the wave passes through with little diffraction.
  • If the gap size is very small relative to the size of the wavelength, the amount of diffraction increases but not much of the wave will pass through the gap.
29
Q

What causes a wave to diffract

A
  • Corners
  • Single edges
  • Gaps
30
Q

What happens when waves hit plane barriers?

A
  • When a wave hits a smooth plane barrier, it is reflected so that its angle of incidence equals the angle of reflection
  • When a wave hits a rough plane barrier, it is mostly refracted; the wave bends and travels through the plane barrier instead of reflecting
31
Q

Interpret reflection and refraction using wave theory.

A

Angle of incidence = angle of reflection