Waves And Electricity

Question 1

Longitudinal waves means

Answer 1

waves in which the medium vibrates/oscillates in the same direction the wave travel in

Question 2

Transverse waves meaning

Answer 2

Waves in which the medium vibrates/oscillates perpendicular to the direction the wave travels in

Question 3

Frequency meaning

Answer 3

The number of vibrations passing each second. The speed of the vibrations making the wave

Question 4

Amplitude meaning

Answer 4

The size of the vibrations. Distance between the equilibrium position and the maximum displacement

Question 5

Absorb meaning

Answer 5

Energy of a wave is taken into the object they hit.

Question 6

Wavelength meaning

Answer 6

Distance over which 1 complete
vibration/oscillation/wave cycle happens.

Question 7

Wavespeed meaning

Answer 7

The speed that a wave propogates (moves away from its source)

Question 8

What is the trough of a wave?

Answer 8

The lowest point on a wave

Question 9

What is the peak of a wave?

Answer 9

The highest point of a wave

Question 10

What is the amplitude of a wave

Answer 10

From peak or trough to the middle

Question 11

Examples of Longitudinal waves

Answer 11

Sound, P – seismic,
Pressure, Shock, slinky

Question 12

Examples of transverse waves

Answer 12

Light, Water, S – seismic, slinky, rope, Electromagnetic radiation (Radio, Micro, IR, visible light, UV, X, Gamma)

Question 13

In a transverse wave what is the direction of vibrations

Answer 13

Up and down

Question 14

In a longitudinal wave what is the direction of vibration

Answer 14

Side to side

Question 15

What are waves a method for

Answer 15

Transferring energy

Question 16

What are waves

Answer 16

A moving disturbance / oscillation / vibration
about a fixed equilibrium point

Question 17

Similarity’s between light and sound

Answer 17

Both travel as waves (they can reflect and refract),
– both are made by vibrations,
– both can transfer energy and information

Question 18

Differences between light and sound

Answer 18

– Light is much faster,
– sound is vibrations of particles (so sound cannot travel in a vacuum),
– light is vibrations of electric and magnetic fields (hence its an electromagnetic wave).

Question 19

How to make shadows

Answer 19

Light travels in straight lines.
Opaque objects do not allow light to travel through them.
When light is shone on an opaque object a shadow forms behind it where the light cannot reach.

Question 20

Why does a banana look yellow

Answer 20

A banana looks yellow because it reflects yellow light into our eyes and absorbs all other colours.

Question 21

Why do black objects look black

Answer 21

they do not reflect any colours

Question 22

Why do white objects look white

Answer 22

they reflect all of the colours of light

Question 23

Red+green light=

Answer 23

Yellow light

Question 24

Red+blue light=

Answer 24

Magenta light

Question 25

Blue+green light=

Answer 25

Cyan light

Question 26

Red+blue+green light=

Answer 26

White light

Question 27

What do filters do?

Answer 27

Filters will only transmit (allow to pass through) certain colours of light (parts of the visible light spectrum)

Question 28

What happens when you use two primary colour filters?

Answer 28

2 primary coloured filters will let no light through

Question 29

What happens to the three primary colours (red, green and blue) when they pass through a coloured filter?

Answer 29

For a red filter, red light is transmitted, blue and green light is absorbed

Question 30

What happens when you put white light through two filters?

Answer 30

Because each filter absorbs two colours of light, all three colours are absorbed.

Question 31

What happens when you shine white light on different coloured paper and why?

Answer 31

Red paper reflects red light, but absorbs the other colours

Question 32

What happens when you shine coloured light on different coloured paper and why?

Answer 32

When red or green light is shone onto blue paper, the blue paper absorbs the red light and it appears dark. When blue light is shone onto blue paper, it reflects the blue light, so when we look at it, it appears to be blue

Question 33

EXTENSION: WHAT HAPPENS WHEN WHITE LIGHT SHINES ON A MAGENTA SURFACE?

Answer 33

When white light shines on a magenta surface, the blue and red parts of the light are reflected, and the green part is absorbed

Question 34

What happens when light travels through different materials?

Answer 34

When light travels in different materials its speed will change. This can make it change direction. We call this change in of speed (and possibly direction) ‘refraction’.

Question 35

Dispersion meaning

Answer 35

Dispersion: Different colours are slowed down by different amounts... which causes them to refract (bend) by different amounts. This causes them to spread out.

Question 36

Order of colours

Answer 36

Bending the least :red Orange Yellow Green Blue Indigo Bending the most:violet

Question 37

How are rainbows made?

Answer 37

The light from the sun is dispersed when it enters each raindrop The colours are reflected from the back of the raindrop

Question 38

How do we hear sound

Answer 38

1.Sound waves are collected by the ear lobe or pinna. 2.The waves travel along the ear canal. The waves make the ear drum vibrate. The small bones (ossicles) amplify the vibrations The cochlea turns these into electrical signals The auditory nerve takes the signals to the brain