That's Entertainment - Waves Section

Question 1

Do particles or energy move along a wave?

Answer 1

Wave energy does, particles do not.

Question 2

What is a crest of the wave?

Answer 2

Top of wave

Question 3

What is the trough?

Answer 3

Bottom of wave

Question 4

What is an amplitude?

Answer 4

The heigh of the crest or trough from it’s rest position

Question 5

What is a wavelenghth?

Answer 5

The length of one wave from crest to crest.

Question 6

What is frequency?

Answer 6

The number of waves passing a point in one second. Measure in hertz (Hz)

Question 7

What is speed?

Answer 7

The distance a wave travels in a certain time (m/s)

Question 8

What do light waves travel as?

Answer 8

Transverse waves

Question 9

What do sound waves travel as?

Answer 9

Longitudinal waves.

Question 10

What is absorption?

Answer 10

Absorption happens with light waves.
• When white light falls on a black object it is absorbed eg. Seeing a coloured object
• Opaque objects do not allow light to penetrate
• Transparent objects allow light to penetrate
• Translucent objects allow some light to penetrate

Question 11

How do we see colours?

Answer 11

Visible light is made up of seven colours, these rays hit an object. All the colours are absorbed except the colour of the object which is reflected into your eyes.

Question 12

What is reflection?

Answer 12

Light waves bouncing off objects
• Angle of incidence = angle of reflection
• Eg. Reflection off a mirror

Question 13

What is refraction?

Answer 13

Bending of light through different matter
• Bend more in a solid as the particles are closer
Together, compared to travelling through a gas where the particles are further apart this causes the light to change its speed
• Eg. Refraction while fishing in water

Question 14

What happens to energy in a sound wave?

Answer 14

When particles begins to vibrate they start to ‘bump’ into each other

Question 15

What happens to sound waves in solids?

Answer 15

The particles vibrate faster as the particles are closer together or more dense so the transfer of energy is much quicker. The sound will travel faster through a solid object.

Question 16

What happens to sound waves in gas?

Answer 16

The particles are less dense or further apart the energy transferred from on particle to another is much slower therefore sound travels through a gas much slower. This is opposite to travelling through solids.

Question 17

Where do sound waves travel slower? Gases, liquids, or solids?

Answer 17

Gases

Question 18

What is the electromagnetic spectrum

Answer 18

The electromagnetic spectrum includes Electromagnetic radiation (EMR), a form of energy that moves as waves as it travels through space.

Question 19

What are gamma rays used for?

Answer 19

Treat cancer, radioactive source

Question 20

What are x-rays used for

Answer 20

X-ray photographs to examine bones, metal objects for cracks, luggage at airports

Question 21

What are ultra violet rays used in?

Answer 21

Fluorescent tubes

Question 22

What is visible light used in?

Answer 22

Seeing and lasers.

Question 23

What is infrared rays used for?

Answer 23

Remote controls in TV’s, cameras, satellites, telescopes.

OPTICAL FIBRE AND COMMUNICATIOn

Question 24

What are microwaves used for?

Answer 24

Cooking in microwave ovens, radar

Question 25

What are radio waves used for?

Answer 25

AM, FM radio, television signal

Question 26

Are waves with the highest frequency have the shortest or longest wavelength?

Answer 26

The shortest. Waves with low frequencies such as radio waves have long wavelengths in order to produce signals to long distances.