Jupiter Mercury and Venus Pluto Further distance to travel in orbit

ellipse Sun Y Z X

5. The picture below represents the path of a comet as it orbits around the Sun. (a) As the comet gets closer to the Sun what happens to the strength of the gravitational force between the comet and the Sun? (b) What happens to the comets speed as it gets closer to the Sun? (c) As the comet nears to Sun it starts to show a tail. In which direction does the tail always point? (d) Explain why the comet starts to show a tail as it gets closer to the Sun. (e) What are comets made of?

increases increases away from Sun heat melts ice rock and ice 5. The picture below represents the path of a comet as it orbits around the Sun. (a) As the comet gets closer to the Sun what happens to the strength of the gravitational force between the comet and the Sun? (b) What happens to the comets speed as it gets closer to the Sun? (c) As the comet nears to Sun it starts to show a tail. In which direction does the tail always point? (d) Explain why the comet starts to show a tail as it gets closer to the Sun. (e) What are comets made of? increases increases away from Sun heat melts ice rock and ice

B - satellite C – the Earth A – distant galaxy D – the Universe

Gravity and speed above fixed point above Earth’s surface 24 hour orbit – same as Earth orbit time is shorter - so see lots of Earth’s surface

Some words may be used once, more than once or not at all 2. Stars form from large clouds of gas and dust. (a) Use the words from the following list to complete the sentences below. Some words may be used once, more than once or not at all Attracts Decreases Electricity Gravity Increases Magnetism Repels Heat Each particle in the cloud __________________ every other particle by a force called ______________ . This force accelerates the particles so their speed ________________. Therefore, the size of the cloud _____________ and the kinetic energy of the particles _______________. As the particles collide with each other they give off energy in the form of ______________ .

Some words may be used once, more than once or not at all 2. Stars form from large clouds of gas and dust. (a) Use the words from the following list to complete the sentences below. Some words may be used once, more than once or not at all Attracts Decreases Electricity Gravity Increases Magnetism Repels Heat Each particle in the cloud __________________ every other particle by a force called ______________ . This force accelerates the particles so their speed ________________. Therefore, the size of the cloud _____________ and the kinetic energy of the particles _______________. As the particles collide with each other they give off energy in the form of ______________ . attracts gravity decreases increases increases heat

What causes the large gas cloud to shrink? 7. The diagram below shows the main possible stages in the life of a star.   What causes the large gas cloud to shrink? (b) At which stage on the diagram is our Sun? (c) Describe the forces acting on the material of the star during this stage. (d) What factor determines the later stages in a stars life i.e. whether it becomes a white dwarf or explodes as a supernova? Black Body

gravity acting inwards is balanced by radiation pressure acting out 7. The diagram below shows the main possible stages in the life of a star.   What causes the large gas cloud to shrink? (b) At which stage on the diagram is our Sun? (c) Describe the forces acting on the material of the star during this stage. (d) What factor determines the later stages in a stars life i.e. whether it becomes a white dwarf or explodes as a supernova? Black Body gravity main sequence gravity acting inwards is balanced by radiation pressure acting out how much Hydrogen is contained in the gas cloud at the start of the stars life

3. The diagram below represents the life cycle of both a small and large mass star. Complete the diagram by adding the correct name of the object next to each stage. Small mass stars Large mass stars

Main sequence / stable stage 3. The diagram below represents the life cycle of both a small and large mass star. Complete the diagram by adding the correct name of the object next to each stage. Small mass stars Large mass stars Gas cloud / nebula Protostar Main sequence / stable stage Red giant Red supergiant Supernova Planetary nebula Neutron star White dwarf Balck Dwarf Black hole

4. Our Sun is currently in its stable period of development. (a) Describe the forces acting on the star during this phase of development. (b) Describe what happens within the Sun for it to go into its next stage of development.

gravity acting inwards is balanced by radiation pressure acting out 4. Our Sun is currently in its stable period of development. (a) Describe the forces acting on the star during this phase of development. (b) Describe what happens within the Sun for it to go into its next stage of development. gravity acting inwards is balanced by radiation pressure acting out Hydrogen gas runs out and complex nuclear reactions cause radiation pressure to increase and be greater than gravity force – Sun will expand to red giant Very dense with high gravity, stopping light escaping At the end of stars life, Hydrogen gas runs out and complex nuclear reactions convert helium to heavier elements

D - towards A – away from C – furthest B – beyond