Sound waves and lenses and black bodies

Question 1

Sound waves are longitudinal or transverse and why

Answer 1

they are longitudinal because they cause particles to vibrate paralleled to the direction of the wave travel.

Question 2

does the speed of sound depend on the medium its travelling through and what speed is that

Answer 2

yes it can

330m/s

Question 3

How does the human ear hear sound

Answer 3

the human ear detects sound. Sound waves enter the ear canal and cause the eardrum to vibrate. Three small bones transmit these vibrations to the cochlea. This produces electrical signals which pass through the auditory nerve to the brain, where they are interpreted as sound.

Question 4

Relationship between frequency and pitch

Answer 4

high frequency = high pitch

low frequency = low pitch

Question 5

How is the amplitude of a sound wave related to the volume of the sound

Answer 5

high amplitude sound waves are loud

low amplitude sound waves are queit

Question 6

Uses of ultrasound

Answer 6

cleaning jewelry

breaking kidney stones

Question 7

How does an ultrasound break apart kidney stones

Answer 7

by vibrating and to break the kidney stones

Question 8

What happens when an ultrasound waves meet the boundary between two different materials

Answer 8

1. Some of the ultrasound waves are reflected at the boundary
2. The time taken for the waves to leave a source and return to a detector is measured
3. The depth of the boundary can be determined using the speed in the material and the time taken.

Question 9

Echo sounding how it work

Answer 9

High frequency sound waves can be used to detect objects in deep water and measure water depth. The time between pulse of sound being transmitted and detected and the speed of sound in water can be used to calculate the distance of the reflecting surface or object.

Question 10

Two types of seismic waves and there type

Answer 10

P-waves are longitudinal

S-waves are transverse waves

Question 11

Properties of P-waves

Answer 11

longitudinal

faster

solid and liquids

Question 12

properties of S-waves

Answer 12

transverse

slower

solids only

Question 13

S-waves are not detected on the opposite side of the earth what does this suggest about the earths core

Answer 13

suggesting the mantle has solid particles but the outer core must be liquid

Question 14

P-waves are detected on the opposite side of the Earth. Refractions between layers cause two shadow zones where no P-waves are detected.

What can we indicate about the earths core from this

Answer 14

The size and positions of these shadow zones indicate there is a solid inner core.

Question 15

A lens

Answer 15

A lens is a shaped piece of transparent glass or plastic that refracts light. When light is refracted it changes direction due to the change in density as it moves from air into glass or plastic

Question 16

Convex lenses

Answer 16

is thicker in the middle than at the edges. This causes parallel lights rays that enter the lends converge. They come together at a point called principal focus.

Question 17

Draw a convex lens in paint ryl quick *****

Answer 17

https://bam.files.bbci.co.uk/bam/live/content/z986rwx/large

Question 18

What is the distance between the lens to the principle focus called

Answer 18

focus length

Question 19

concave lens

Answer 19

is thinner in the middle than edges. This causes paralleled rays to diverge. They separate but appear to come from a principle focus on the other side of the lens

Question 20

Draw concave lens e.g

Answer 20

https://bam.files.bbci.co.uk/bam/live/content/z8qnk2p/large

Question 21

What can images be formed by a lens can have the following properties

Answer 21

Upright or inverted

Magnified or diminished

Real or virtual

Question 22

Difference between a real image and a virtual image

Answer 22

A real image is an image that can be projected onto a screen. A virtual image appears to come from behind the lens.

Question 23

For a camera or human eye looking at a distant object twice the focal length what is the images properties

Answer 23

inverted

diminished

real

Question 24

Projectors contain convex lenses what are the properties from one or two focal lengths away

Answer 24

inverted

magnified

real

Question 25

Magnifying glass uses a convex lens what are the properties when an object is less than a focal length away

Answer 25

upright

magnified

virtual

Question 26

Concave lenses always produce images that are

Answer 26

upright

diminished

virtual

Question 27

What occurs in terms of energy if a a material absorbs waves

Answer 27

this will usually increase the internal energy of the particles

Question 28

If an object is all black can it absorb coloured light

Answer 28

it absorbs all the wavelengths of visible light.

Question 29

All bodies emit and absorb _________ ___

Answer 29

infrared radiation

Question 30

if a body is hot what properties will it have

Answer 30

the more infrared radiation it gives out in a given time

The greater the proportion of emitted radiation is visible light

Question 31

what is a perfect black body and its properties

Answer 31

a theoretical object

It would absorb all radiation that falls on it

it would not reflect or transmit any radiation

Question 32

Why are stars considered to be black bodies

Answer 32

because they are very good emitters of most wavelengths in the EM spectrum

Question 33

Required practical
Investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface

Answer 33

1. Place a Leslie cube on a heat-resistant mat. Fill it, almost to the top, with boiling water and replace the lid.
2. Leave for one minute. This is to enable the surfaces to heat up to the temperature of the water.
3. Use the infrared detector to measure the intensity of infrared radiation emitted from each surface, or the temperature of the surface. Make sure that the detector is the same distance from each surface for each reading.

Question 34

Required practical
Investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface

hazard consequence and control measures

Answer 34

boiling water

scalds

pour water slowly using a funnel if necessary. Do not move the Leslie cube until it has cooled

Question 35

Factors effecting earths temp

Answer 35

concentration of green house gases such as water vapor methane and carbon dioxide

the rate at which light radiation and infared radiation are absorbed by the earths surface and emitted by the earths surface

Question 36

When visible light and high frequency infrared radiation are absorbed by the surface of the Earth, the planet’s internal energy ______ and the surface gets ______. Some of the energy transiffered to the atmosphere by ___________ and ___________

Answer 36

increase hotter conduction convection