Topic 6a- Properties of waves

Question 1

Define a wave.

Answer 1

An oscillation or vibration passing through a medium. It transfers energy, not matter.

Question 2

What is a transverse wave?

Answer 2

A wave where the oscillations of particles are at right-angles to the direction of the energy transfer.

Question 3

Define longitudinal waves?

Answer 3

The oscillations of the particles are parallel to the direction of the energy transfer of the wave. This causes areas of compression and rarefaction.

Question 4

What is wavelength?

Answer 4

Distance between two identical points on successive waves.

Question 5

Define frequency.

Answer 5

The number of waves (complete oscillations) that pass a point every second.

Question 6

What is frequency measured in?

Answer 6

Hertz (Hz)

Question 7

What equation can be used to calculate frequency?

Answer 7

Frequency = number of waves / time

Question 8

What is wavelength measured in?

Answer 8

Meters.

Question 9

What is wavespeed measured in?

Answer 9

m/s (ms^-1)

Question 10

What is the speed of sound in air?

Answer 10

~330 m/s

Question 11

What is the equation for percentage uncertainty?
(2 possible answers)

Answer 11

Percentage uncertainty = resolution / value
or
(half range / mean) x 100

Question 12

What is the frequency of ultrasound waves?

Answer 12

Greater than 20000 Hertz

Question 13

Which part of the ear vibrates and amplifies sound?

Answer 13

Ear drum and ossicles.

Question 14

What is the term used to describe reflection from a smooth surface? (e.g. a mirror)

Answer 14

Specular reflection.

Question 15

What is the term used to describe reflection of light from an irregular surface? (e.g. white paper)

Answer 15

Diffuse reflection

Question 16

What are the three possible things that happen to a wave when they are incident on a boundary?

Answer 16

Reflected, transmitted and absorbed.

Question 17

What is refractive index?

Answer 17

The speed of light through a medium.

Question 18

The quicker light travels through a medium ______

Answer 18

the more it bends away from the normal

Question 19

What is a real image?

Answer 19

Rays converge having passed through a lens. Image can be projected on a screen.

Question 20

What is a virtual image?

Answer 20

Rays diverge having come through a lens. Light appears to have come from a different place.

Question 21

What are the two types of seismic wave and where do they come from?

Answer 21

Surface and body waves. Seismic waves are produced by earthquakes.

Question 22

What are surface waves (a type of seismic wave)?

Answer 22

Travel across the surface of the earth.

Question 23

What are body waves (a type of seismic wave)?

Answer 23

Travel through the core of the earth.

Question 24

What are primary waves (p-waves)?

Answer 24

(From an earthquake-)
Travel through solid and liquid.
Travel faster than secondary waves.
Longitudinal waves.

Question 25

What are secondary waves (s-waves)?

Answer 25

(From an earthquake-)
Travel through solids only.
Slower than primary waves.
Transverse.

Question 26

Where is the p-wave shadow zone in degrees?

Answer 26

105-140

Question 27

All images formed by concave lenses are…

Answer 27

Upright, virtual and diminished.

Question 28

All images formed by convex lenses are…

Answer 28

Inverse and virtual.

Question 29

What three things could happen to a wave at a boundary?

Answer 29

• absorption
• reflection
• transmission (often undergoing refraction)

Question 30

WHat is the period of a wave?

Answer 30

The amount of time it takes for a full cycle of the wave to be complete.
Calculated with →
period = 1 / frequency

Question 31

The slower a wave is travelling through a medium…

Answer 31

The more it bends towards towards the normal

Question 32

Where are the angles of incidence and refraction?

Answer 32

• the angle of incidence is between tge incoming ray and the normal
• the angle of refraction is between the refracted ray and the normal