Waves and Light

Question 1

Refraction

Answer 1

This is the bending of light due to the different densities of the substances involved. This is also known as refractive index these have no values they are ratios. Air has a refractive index of about 1.00.

Question 2

Waves

Answer 2

Transfer energy from one place to another

Question 3

Intensity and amplitude

Answer 3

Intensity is used to measure waves (Wm^-2) Measure of energy per unit time travelling through a unit area perpendicular to the direction of travel.

Amplitude is the maximum displacement of a particle in a wave form its units are (m).

Question 4

Electromagnetic and mechanical waves

Answer 4

Electro: Not necessarily needing a medium can propagate via a vacuum.

Mechanical: Travels through a medium and transport particles of the medium oscillate around their rest position.

Question 5

Pulses, continuous and seismic waves

Answer 5

Pulses: Single wavefront travelling through a medium.
Continuous: repeating waves passing through a medium.
Seismic: Body waves that propagate within the ground.

Question 6

Longitiudinol and transverse

Answer 6

Longitudinal: Particles oscillate about a mean position in the same line as the direction of travel of the wave.
P waves are longitudinal compression and rarefaction waves (Primary wave).

Transverse: Particles oscillate about a mean position perpendicular to the direction of travel by the wave.
S waves are transverse waves called sheer waves (secondary)

Question 7

Wave features

Answer 7

Can be graphed on displacement vs time or displacement vs distance graph.

Speed depends on material and state, speed differences between materials in some states are affected by density.
Higher density sluggish reaction.
The speed of a wave in the air depends on temperature and humidity.
Temperature affects mostly as it impacts density.
Increased tension, increased speed, and properties of a medium also affect speed.

Question 8

Frequency and velocity of wave

Answer 8

F = 1/time

V = wavelength/time (the period which is the time taken for a full wave to pass a given point.)
V = Frequency x time

Question 9

Speed of sound and light

Answer 9

Sound: 330ms^-1
Light: 3 x 10^8 ms^-1

Question 10

Snells law

Answer 10

N1sintheta1 = N2sintheta2

Question 11

Focal Length

Answer 11

1/F = 1/u + 1/v

U is the object distance
V is the image distance
F is the focal length

Question 12

Electromagnetic spectrum wavelength

Answer 12

All Electromagnetic spectrum wavelengths travel at ‘c’ is a vacuum.

C= 3 x 10^8 ms^-1