The Solar System & Lifecycles of Stars (Edexcel GCSE Physics)

Which of these planets is at the greatest distance from the Sun?

Use words from the box to complete the following sentences.

(i) Saturn is a ............................................................

[1]

(ii) The Moon is a ............................................................

[1]

(iii) Halley’s Comet orbits a .................................................

[1]

Figure 3 shows a Mars Exploration Rover.

Figure 3

The mass of the rover is 190 kg.

i) The gravitational field strength on Earth is 10 N/kg.

Calculate the weight of the rover on Earth.

Use the equation

weight = mass × gravitational field strength

weight on Earth = ................................................ N[1]

ii) The weight of the rover on Mars is 700 N.

Calculate the gravitational field strength on Mars.

gravitational field strength on Mars = ....................... N/ kg[2]

The Asteroid Belt is part of our Solar System.

Vesta is an asteroid in the Asteroid Belt.

Vesta orbits the Sun between the orbits of

Vesta has an orbital speed of 1.9 × 10⁴ m/s.

Vesta travels a distance of 2.2 × 10¹² m when it orbits the Sun once.

Calculate the time taken for Vesta to orbit the Sun once.

time = ............................................................. s

Higher Tier Only

Explain why Vesta is accelerating even when it is travelling at a constant speed.

Higher Tier Only

Energy is transferred from the Sun to Vesta by radiation.

Explain why the temperature on Vesta does not continue to rise, even though it is absorbing energy from the Sun.

The distance between Vesta and the Sun is 2.4 AU.

1AU is the distance between the Earth and the Sun.

The intensity of the Sun’s radiation reaching the Earth is 1400 W/m².

1W = 1 J/s

The intensity of the Sun’s radiation at a distance, d, from the Sun is given by the equation

where K always has the same value.

i) State the unit of K.

[1]

ii) Calculate the intensity of the radiation from the Sun at Vesta.

intensity = ............................................................. W/m² [3]

Describe how stars are formed.

Explain why the star remains stable during the main sequence phase.

The life cycle of a star following the main sequence period depends on the size of the star.  A particular star is much larger in size than the Sun. 

Complete the stages of the life cycle of this star.

Describe what happens in the red giant phase.

Rearrange the stages of the life cycle of a star into the correct order.

A star can be in its main sequence phase for billions of years.

Figure 1 shows the forces acting on the Sun during this stable stage of its life cycle. 

Figure 1

(i) State the name of the force pulling inwards.

[1] 

(ii) Explain what causes the force pushing outwards.

[1]

Two stars, Alpha Centauri B and Betelgeuse have solar masses of 0.9 and 16.5 respectively. The mass of the Sun is 1 solar mass.

Explain which star could eventually become a neutron star.

For stars with much larger masses than our Sun, the first 4 stages are almost exactly the same as for lower mass stars. For the later stages the processes begin to differ.

Compare and contrast the final two stages in stars with much larger masses than our Sun and stars with similar masses to our Sun.

Some main sequence stars become black holes.  

Describe the evolution of a main sequence star to the point at which it becomes a black hole. 

State and explain whether the Sun will eventually become a black hole. 

The table gives some information about gravitational field strength.

An identical 10 kg object is sent to each planet.

(i) State on which planet the object will have the greatest weight.

[1]

(ii) State on which planet the object will have the least weight.

[1]

Describe the differences between the heliocentric and geocentric models of the solar system.

The Sun has a mass of 2.0 × 10³⁰ kg.

A white dwarf has a mass of 3.4 × 10²⁹ kg.

Calculate the value of

value = ..............................................................

Figure 4 is a diagram giving some information about main sequence stars.

Luminosity is a measure of how bright something is.

An increase in luminosity means an increase in brightness.

Figure 4

i) Estimate the temperature of the Sun.

temperature of the Sun = .................................... K[1]

ii) State how the brightness of a main sequence star changes with its temperature.

[1]

iii) State how the brightness of a main sequence star changes with its mass.

[1]

Nuclear fusion provides the energy source for stars including the Sun.

Describe what happens during nuclear fusion.

A nebula may evolve into a main sequence star, such as the Sun.

Explain how a nebula may evolve into a main sequence star.

Figure 1 shows the 5 stages of the life cycle of a star that has a similar mass to the Sun.  

 Figure 1  

State and explain what happens in stage 2 of Figure 1. 

Include details of the forces involved and what they depend on.

State and explain what happens in stage 4 of Figure 1.

The average length of time a star stays in stage 3 is 10⁹ to 10¹¹ years. 

Explain why the star remains stable during stage 3 for this length of time.

For stars with much larger masses than our Sun, stages 1 to 3 in Figure 1 are almost exactly the same as lower-mass stars. The processes begin to differ for the later stages, 4 and 5.

Compare and contrast the final two stages in stars with much larger masses than our Sun and stars with similar masses to our Sun.

Figure 1 contains information on the mass of different stars. 

Figure 1  

Compare the masses of Proxima Centauri and VY Canis Majoris to the Sun.

Explain how these differences will affect the time these stars can remain stable.

Describe what will happen to each of the stars after they leave the main sequence stage.