reflection, refraction and sound

Question 1

when waves reach the boundary of a medium what could happe?

Answer 1

they could reflect,absorb refract,or transmit

Question 2

what are the mian afctos for constructing a ray diagram?

Answer 2

rays must be drawin wit a ruler

• each ray should have an arrow drawn on them
• when the ray meets boundary a normal should be drawn at right angle to the boundary

-all relevant angles should be labelled

Question 3

What does refraction depend upon?

Answer 3

The angle at which the wave hits the boundary,and the materials involved

Question 4

What is the refractive index?

Answer 4

The way in which a material affects refraction

Question 5

Refraction is due to the_____?

Answer 5

The wave speed in different media

Question 6

What is an ultrasound wave always greater than?

Answer 6

20 kHz

Question 7

What happens when an ultrasonic wave meets a boundary between two different medi

Answer 7

It is partially reflected

Question 8

How do you determine how far a way a boundary is?

Answer 8

Measure the time taken for reflected ultrasonic waves to return to a detector

Question 9

What is uktr around usually used for?

Answer 9

Medical uses e.g. finding kidney stones,tumours,and foetuses

Question 10

What is echo sounding used for?

Answer 10

Detecting objects in deep water and measuring the depth of water

Question 11

In echo sounding what exactly happens?

Answer 11

The wave travels through the water and reflects back after hitting something and the time taken for the wave to come back determines the distance

Question 12

What is the equation for echo sounding?

Answer 12

Distance=speed X time

Question 13

What is the “speed” in the echo sounding equation?

Answer 13

1500m/s as this is the general speed of sound in water

Question 14

What are the two types of seismic waves performed in earthquakes?

Answer 14

P-waves and s-waves. Primary and secondary waves

Question 15

What are the features of p-waves?

Answer 15

They are longitudinal waves

The travel at the speed of sound and are twice as fast as S-waves

They travel at different speeds through solids and liquids

Question 16

What are the features of S-waves?

Answer 16

They are transverse waves

They are not able to travel through liquids

Question 17

when talking about waves What three things happen in an earthquake?

Answer 17

1. Seismic waves travel outwards from the earthquake and are capable of travelling all the way through the earth
2. seismic waves travel in a curved path through the earth due to the earth’s increasing density with depth
3. Protective placed around the earth measure when and where the different waves arrive

Question 18

What are the two different shadow zones?

Answer 18

S-wave shadow zone and P-wave shadow zone

Question 19

What are the features of the s wave shadow zones?

Answer 19

S waves are not able to travel through the liquid outer core of the earth

this results in a large shadowzone on the opposite side of the earth to where the earthquake originated

The Shadow zone provides evidence of the size of the earth’s core

Question 20

P-wave shadow zone features:

Answer 20

P waves are able to travel through the liquid outer core

however they are refracted at the boundary between the semi-solid mantle and the liquid

They are refracted again on the boundary between the liquid outer core and solid inner core

These refractions result in p wave shadow zones

The study of these shadow zones is used to determine the size and composition of the inner and outer core