Chapter 16 - Waves & Wave Motion

Question 0

Explain:

Electromagnetic waves

Answer 0

Electromagnetic waves do not need a medium (eg light waves, radio waves, microwaves, UV waves).

Question 1

Explain:

Mechanical waves

Answer 1

Mechanical waves must have a medium in which to travel (eg water waves, waves on a rope or spring, sound waves).

Question 2

Define:

Travelling Wave

Answer 2

A travelling wave, either mechanical or electromagnetic,

• is a disturbance that travels out from the source producing it,
• transferring energy from the source to other places through which it passes.

Question 3

Define:

Travelling Mechanical Wave

Answer 3

A travelling mechanical wave is a disturbance carrying energy through a medium without any overall motion of that medium.

Question 4

Define:

Transverse Wave

Answer 4

A transverse wave is a wave where the direction of vibration is perpendicular to the direction in which the wave travels (eg waves on water, rope or sting, sound waves).

Question 5

Define:

Longitudinal Wave

Answer 5

A longitudinal wave is a wave where the direction of vibration is parallel to the direction in which the wave travels (eg sound waves, ultrasonic waves, compression waves on a spring).

Question 6

Name 7 terms to describe Transverse wave

Answer 6

1. Crest - top of wave
2. Trough - bottom of wave
3. Amplitude -A the height it reaches
4. Vibrating source
5. Cycle - one trough and crest
6. Wavelength - distance from two crests or trough
7. Frequency

Question 7

Explain:

Frequency (f)

Answer 7

Is the number of cycles passing any point in 1 sec ( i.e. per second)
Unit: 1Hz = 1 s-1

Question 8

Name 4 terms to describe Longitudinal waves

Answer 8

1. Cycle - one compression and one rarefaction
2. Amplitude - max distance from u disturbed position
3. Wavelength - any point in one cycle to the corresponding point on the next cycle
4. Frequency

Question 9

Properties of Waves (5)

Answer 9

1. Reflection
2. Refraction
3. Interference
4. Diffraction
5. Polarisation ( for transverse waves only)

Question 10

Define:

Reflection

Answer 10

The bouncing of waves off of an obstacle in their path is called reflection.