Core Physics

Question 1

What did the polish astronomer Nicolaus Copernicus notice about Ptolemys measurements and what model did he thus create?

Answer 1

That they fit a model with the sun at the centre, now named the heliocentric model.

Question 2

When was the telescope invented and what is it used for?

Answer 2

At the end of the 16th century. It allowed scientists to see objects in space in much greater detail than the naked eye and to find new objects.

Question 3

What did Nicolaus coppernicus discover which disproved the geocentric model?

Answer 3

4 of jupiters moons and by plotting their movements he showed that not everything orbited the Earth, as well as other observations.

Question 4

Luminous objects give out ____ which travel as ______.

These allow people to study____.

Answer 4

Visible light, waves of energy, distant objects

Question 5

Photography has helped astronomers do what?

Answer 5

Make more detailed observations than they could by just making drawings.

Question 6

Two examples of energy-carrying waves that objects in space emit, not including visible light.

Answer 6

Microwaves, radio waves

Question 7

What did Thomas Harriet (1560-1621) observe and with what?

Answer 7

He observed the moon With the telescope allowing him to see it in greater detail, he made the first drawings of its craters.

Question 8

The change of direction of light when it moves into a different material

Answer 8

Refraction

Question 9

Where does refraction occur?

Answer 9

At the interface(boundary) between two materials

Question 10

A line at right angles to the interface is called the _____ line

Answer 10

Normal

Question 11

Definition of a lens

Answer 11

A transparent block that has been shaped so that its interface changes the direction of parallel light waves.

Question 12

Definition of a converging(or convex) lens and what it does

Answer 12

A glass block that is curved on both sides to make it thicker in the middle, light rays entering a lens are brought together a.k.a converge

Question 13

The distance between the focus and the lens is called the _____ of that lens

Answer 13

Focal length

Question 14

How can the focal length of a converging lens be found?

Answer 14

By focusing the image of a distant object onto a piece of paper and measuring the distance between the lens and the screen(in this case the paper of which the image is in focus on).

Question 15

How does a refracting telescope work?

Answer 15

A convex lens(the objective lens) created an image of inside the tube and another lens(the eyepiece lens) is used to magnify this image.

Question 16

Why does refraction occur?

Answer 16

Because light travels at different speeds in different materials.

Question 17

The magnification of converging lenses depends on what?

Answer 17

How curved their surfaces are and how closely together they are placed.

Question 18

What is a real image?

Answer 18

An image in which the Rays of light actually meet at the point where the image is seen

Question 19

Where can virtual images be seen and explain what it is

Answer 19

In a mirror, in a virtual image the Rays of light appear to come from an image but do not actually come from that image. A virtual image cannot be shown on a screen.

Question 20

What the fact that waves are reflected between different boundaries mean?

Answer 20

Whenever a light passes through a lens, some is reflected. This makes the image fainter. This can be a problem for refracting telescopes if e.g a star is already very faint.

Question 21

What did Greek Astronomer Ptolemy (c. 90-168) discover and how did he do it?

Answer 21

The fact that the sun, Moon and planets moved in orbits. His idea put Earth at the centre of everything and it is therefore called the Geocentric model
He did it by taking detailed measurements of the movement of objects in the sky.

Question 22

What improves magnification in refracting telescopes?

Answer 22

Large length and larger lenses

Question 23

What is the problem of using large lenses in refracting telescopes?

Answer 23

They are very heavy and are difficult to make into perfect shape, meaning that the images have distorted colours.

Question 24

How does a reflecting mirror work?

Answer 24

The curved primary mirror focuses parallel light rays from a distant object to an image in the same way as the objective lens in a refracting telescope. the image is then magnified by the eyepiece lens, also like a refracting telescope.

Question 25

How, can one improve the maximum viewing distance of a reflecting telescope?

Answer 25

By having a large in diameter primary mirror to be able to collect tiny amounts of light and therefore allow as much light to enter as possible.

Question 26

What is the movement of individual particles like in a transverse wave?

Answer 26

The particles move at right angles to the direction that the wave is going

Question 27

Type of wave are electromagnetic waves?

Answer 27

Transverse

Question 28

Do electromagnetic waves need a medium through which to travel?

Answer 28

No

Question 29

What are longitudinal waves like?

Answer 29

The particles move back and forth in line with the direction that the wave is going

Question 30

What type of waves are sound waves?

Answer 30

Longitudinal

Question 31

Earthquakes and explosions produce what kind of waves?

Answer 31

Seismic waves which travel through the earth. Solid rock material can be pushed or pulled (longitudinal seismic waves) or moved up and down or side to side(transverse seismic waves).

Question 32

Wave frequency is what and what is its unit?

Answer 32

The number of waves passing a point each second, it is measured in hertz(Hz). a frequency of 1 hertz means 1 wave passing per second.

Question 33

What is wavelength and what is it measured in?

Answer 33

The distance from a point on one wave to the same point on the next wave, measured in metres.

Question 34

What is amplitude and how is it measured?

Answer 34

The maximum distance of a point on the wave from its resting position, measured in metres.