Yr 9 Physics (Waves)

Question 1

What is a wave?

Answer 1

A wave is a propagation of a disturbance in a regular and organised way

Question 2

What are the two types of waves?

Answer 2

Transverse and Longitudinal (Compression) Waves

Question 3

Characteristics of a Transverse wave

Answer 3

Wave in which the particle motion is perpendicular to the direction the wave is travelling

Question 4

Characteristics of a Longitudinal wave

Answer 4

Waves in which the particle motion is parallel and on the same axis

Question 5

What is superpositon?

Answer 5

When waves travel through each other. When they collide they will add together. If a identical strength wave is sent reversed to another wave they cancel each other out

Question 6

Difference between travelling and standing wave

Answer 6

A travelling wave is a wave which is travelling. A standing wave where the nodes of the wave are not moving while the antinodes vibrate at maximum amplitude

Question 7

Transverse wave examples

Answer 7

Ocean waves, seismic S-waves and electromagnetic waves

Question 8

Longitudinal wave examples

Answer 8

Sound waves, Tsunami waves and seismic P-waves

Question 9

Compressions vs Rarefractions

Answer 9

Compressions are regions where particles are closer together (high pressure). Rarefractions are regions where particles are further apart.

Question 10

What are mechanical waves and what are some examples?

Answer 10

Waves which need a medium for travel. Sound is an example of a mechanical wave and electromagnetic waves are not mechanical waves

Question 11

What is Frequency

Answer 11

How many wave cycles pass by at a given time. Measured in hertz (hz) 1 hertz = 1 wave/s

Question 12

What is velocity

Answer 12

Speed of a wave, often in m/s

Question 13

What is wavelength

Answer 13

Distance between each identical point on a wave. Represented by Greek Lambda symbol

Question 14

Equation describing relationship between Velocity, Wavelength and Frequency

Answer 14

Velocity = Wavelength * Frequency

Question 15

Angle of Incidence = ???

Answer 15

Angle of Reflection

Question 16

What is Refraction

Answer 16

When light passes from one medium to another it can change direction due to the fact that light travels at different speed through different materials. Different materials have a different refractive index

Question 17

Resonance

Answer 17

Refers to the natural frequencies objects like to vibrate at (called the resonant frequencies) and how waves of the same frequency hitting an object can cause it to vibrate at an increased amplitude

Question 18

Concave Lenses

Answer 18

Diverging lenses that make light rays diverge. Used for nearsighted people. Has a theoretical focal point in front of the lens

Question 19

Convex Lenses

Answer 19

Converging lenses that make light converge on a focal point. Used for long-sighted people