4.2 What Is A Wave? Flashcards Preview

Physics Chapter 4 - Oscillations And Waves > 4.2 What Is A Wave? > Flashcards

Flashcards in 4.2 What Is A Wave? Deck (24):
1

What is a wave?

Propagation of a disturbance through a medium.

2

What happens as a wave travels through the medium?

Molecules of the medium are displaced from equilibrium positions, made to oscillate about these positions in simple harmonic motion.

3

What can a wave transfer?

Energy and momentum.

4

What are some examples of mechanical waves?

Water waves, sound, earthquake waves.

5

What medium do mechanical waves travel through?

Require a physical medium, cannot propagate in vacuum.

6

What is the wave speed determined by for mechanical waves?

Determined by the properties of the medium.

7

What is the disturbance of particles in mechanical waves?

Change of a property of the medium from its equilibrium value - when there is no waves.

8

What are some example of electromagnetic waves?

Light, radio waves, X rays, infrared radiation, ultraviolet radiation.

9

What medium do electromagnetic waves travel through?

Can propagate in a vacuum as well as various physical media.

10

What is the wave speed determined by for electromagnetic waves?

In vacuum all waves travel at 3x10^8 ms^-1

11

What is the disturbance of particles in electromagnetic waves?

The oscillating values of electric and magnetic fields.

12

What is displacement?

Vector to the position of a point in a medium from the equilibrium position of the point.

13

What is amplitude?

Maximum displacement.

14

What is a crest?

Maximum positive displacement.

15

What is a trough?

Maximum negative displacement.

16

What is wavelength?

Length of a full wave. May be found from a displacement versus distance graph.

17

What is frequency?

Number of full waves produced by a source in 1 second - in Hz. Frequency is inverse of period f = 1/T

18

What is period?

Time taken fro one full wave to pass by. May be found from a displacement versus time graph. Period is inverse of frequency T = 1/f

19

What is wave speed?

Speed at which a crest moves past an observer at rest in the medium. v = f x lambda

20

What is intensity?

Power transferred per unit area by a wave. Proportional to the square of the amplitude. For a point source emitting uniformly in all direction, intensity a distance d from point source has intensity proportional to 1/d^2.

21

What is a transverse wave?

Displacement of medium is perpendicular to direction of wave movement or energy transfer.

22

What is a longitudinal wave?

Displacement of medium is parallel to direction of wave momentum or energy transfer.

23

What is a ray?

Lines indicating the direction of energy transfer of a wave.

24

What is a wavefront?

Surface at right angles to rays. All points on a wavefront have the same phase.