Space

Question 1

What is the universe made up of?

Answer 1

Billions of galaxies.

Question 2

What does each galaxy contain?

Answer 2

It contains hundred of millions of stars.

Question 3

What is the solar system made up of?

Answer 3

It is made up of:
one star- the sun
planets and dwarf planets that orbit the sun
asteroids and comets that also orbit the sun
moons that orbit planets–natural satellites.

Question 4

What is a nebula?

Answer 4

Cloud of dust and gas which was pulled together by gravitational attraction.

Question 5

How are protostars created?

Answer 5

As the dust and gas were drawn together, they collided, increasing the temperature and creating a protostar and then eventually a main sequence star.

Question 6

How is a main sequence star created?

Answer 6

Material is drawn by gravity these collisions increase until the temperature and pressure is high enough for hydrogen nuclei to fuse together forming helium and a main sequence star.

Question 7

What happens to the material that is not drawn into the sun?

Answer 7

It remains in the orbit and forms the planets and other objects in our solar system.

Question 8

What does the sun’s stability result in?

Answer 8

The stability is the result of the balance between :
The fusion energy trying to expand the sun
gravity acting inwards trying to collapse the sun.

Question 9

How do the different sizes of stars end up?

Answer 9

Small stars (eg the sun) - end up as black dwarf stars.
Larger stars become neutron stars
The largest stars become black holes.

Question 10

How do stars begin?

Answer 10

Clouds of dust and gas are drawn together by gravity to form a protostar and eventually a main sequence star.

Question 11

What happens during a main sequence star?

Answer 11

Hydrogen fuses together to create helium and in large stars lithium.

Question 12

What happens as the star ages?

Answer 12

1) Mass transforms into energy through nuclear fusion.
2)As mass decreases the outwards force becomes larger than the force from gravity.
3) The star expands then cools becoming a red giant or a red super giant.
4) As the star cools and the hydrogen fuel is used up the outward forces are reduced.
5) Star collapses inward due to gravity causes increase in temperature.
6) It begins to fuse helium and lithium.

Question 13

What does the largest star become?

Answer 13

A supernova- releases energy and scatters material of the star into space.

Question 14

How are new elements formed?

Answer 14

They are formed in stars by nuclear fusion.

Question 15

What does the planet orbit and what does the
moon orbit?

Answer 15

The planets orbit the sun.
The moons orbit a planet.

Question 16

How do objects, planets and satellites travel in a circular path? What does this result in?

Answer 16

For an object, there must be a force that acts towards the centre of the circle.
For planets and satellites, it is the force of gravity that acts toward the centre.
This results in an acceleration towards the centre.

Question 17

What happens to an object undergoing circular motion?

Answer 17

• The acceleration does not cause the object to change speed.
• The acceleration causes the object to change direction.
• The velocity changes but the speed remains the same.
• The instantaneous (occurring) velocity is perpendicular to the centripetal (force that acts on an object to keep it moving along a circular path) force.

Question 18

How do you stay in a stable orbit?

Answer 18

To stay in a stable orbit, at a particular distance from a large body, the smaller body must move at a particular speed.