P11 Waves

Question 1

What is a wave?

Answer 1

The transfer of energy from one place to another withought transfering matter (stuff)

Question 2

What happens when a wave goes through an object?

Answer 2

The energy of the wave will cause the object’s atoms to ossilate and transfer energy between them.

The atoms will ultimatly stay in the same place. When the ossilate they are just moving up and down or sideways.

Question 3

What is the amplitude of a wave?

Answer 3

The maximum displacement from the undisterbed position (crest- middle)/(trough to the middle)

Question 4

What is the wavelength?

Answer 4

The distance from 1 point on a wave to the same point of the wave next to it

Eg crest to crest

Question 5

What is Frequency

Answer 5

The amount of complete waves which can lass through a point in 1 second

Measured in Hz (Hertz)

1Hz = 1 wave per second

Question 6

What is the period of a wave. How do you calcuate it?

Answer 6

The amount of time it takes a full cycle of a wave to pass through a point

T = 1/F

Period(seconds) = 1/Frequency(Hz)

Question 7

What is a transverce wave?

Answer 7

When the ossilations are perpedicular to the direction of energy transpered.

If a wave is traveling to the left the ossilations will go up and down

Question 8

Give an example of a transverse wave

Answer 8

All electromagnetic waves … light

Ripples in water

Question 9

What is a longitudinal wave

Answer 9

A wave the ossilations travel at the same direction (parrelel) to the direction of the energy transfer

The the wave is tranfering energy to the left the ossilations will be left to right

Question 10

What is an example of Longitudinal waves

Answer 10

Sound waves

Question 11

What is rarefractions and compressions?

Answer 11

These are found in longitundinal waves

Rarefractions are where there are large gaps between each molecule in the wave
Compressions are where there are small gaps between each molecule in the waves

They will be in alternating order.

An area of rarefraction will be follwed by an area of compression.

Question 12

How do you calcuate Wave Speed?

Answer 12

Ws= F X Wl

Wave Speed(m/s) = Frequency(Hz) X Wave Length(meters)

Or

V =fλ

Or

WS = D/T

Wave Speed(m/s) = Distance(M)/Time(s)

Question 13

What is wave speed?

Answer 13

The speed of which energy is being traveled

Question 14

Exam Trick - If someone is measure the speed of a wave that bounces off a wall what do you need to remember?

Answer 14

That the wave has traveled to the wall and back. Therfore if they say that the distance to the wall is 6m you need to double that and use 12m.

Question 15

What effects the pitch of a wave in sound waves?

Answer 15

The wavelength and frequency

Question 16

What effects the color of the wave in a light wave?

What effects the intensity of the light in light waves?

Answer 16

Wavelength and frequency

The amplitude

Question 17

How fast does light travel?

Answer 17

300,000,000m/s

Question 18

What is speed sound in air and in a solid?

Answer 18

Air - 340m/s

Solid - 2,500m/s

Question 19

What type of wave does an earthquake produce?

Answer 19

Bolth

The primary wave is a longitudinal wave (less powerfull warning wave)

Hovever

The secondary wave is a transverce wave (destructive wave)

The reason why there are 2 different waves in an earthquake is because longitunial and transverce waves travel at different speeds.

Question 20

When a wave meets a boundary 3 things could happen.

What determines which will happen?

Answer 20

Absorbed

The enery of the wave gets transfered into the energy stores of the material. Often this will be as heat energy

Transmitted

The wave will travel through the material. This can often lead to refraction. This often halpens with waves used for communication.

Reflected

The wave isn’t absorbed or transmitted but instead is sent back away from the material (angle of incidence = the angle of reflection on a flat object). This is how echos are created.

What hapens is dependent on the wavelength of the wave and the properties of the materials involved.

Question 21

What is refraction?

Answer 21

The prosses when waves change direction at a boundary

If the wave hits the object along the normal (90*) it will not refract

If the wave hits the object along any other angle it will refract.

Question 22

Which way does the wave refract?

Answer 22

If the wave speeds up when it hits the object then it will start to away from the normal (90*)

If the wave slows down when it hits the object then it will start to move towards the normal (90*)

Question 23

How much are the wave refracted?

What determines how fast the wave will speed up or slow down?

Answer 23

This depends on how much the wave speeds up or slows down. This is normaly determined by the density of the materials.

Usualy the higher density the material is the slower the wave travels through it

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Question 24

What is optical density?

Answer 24

How quickely light can travel through something?

The higher the optocal density the slower light waves travels through it

Question 25

When a wave is refracted what changes?

Answer 25

Wavelength chenges as the wave speeds up or slows down

However

The frequency stays the same

Question 26

What is a ray diagram?

Answer 26

A diagram that shows the direction waves are traveling in and the angels that it hits the obstical at.

Question 27

How do you draw a ray diagram?

Answer 27

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Question 28

Wave Frount diagrams: possibel needed

Answer 28

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