Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Astrophysics
156 practice questions
Topics covered
Practice questions
71–80 of 156
Question 71
5 marks · Normal
Answer and see the solution →A communication satellite is placed in orbit 36,000 km above Earth's surface. The radius of Earth is approximately 6,400 km.
(a)[1 mark]Calculate the total orbital radius of the satellite from the centre of the Earth.
(b)[2 marks]Explain why artificial satellites in low orbits move faster than satellites in high orbits above the same planet.
(c)[2 marks]The communication satellite takes exactly 24 hours to complete one orbit. Calculate its average orbital speed in km/s (show all working).
Question 72
1 mark · Easy
Answer and see the solution →State the name of the galaxy in which our Solar System is located.
Question 73
1 mark · Easy
Answer and check →Which of the following star classes is the hottest according to the classification system?
- A.O
- B.A
- C.G
- D.M
Question 74
2 marks · Easy
Answer and see the solution →Describe the overall shape of the Milky Way galaxy and state where the Sun is positioned within it.
Question 75
2 marks · Easy
Answer and see the solution →A blacksmith heats a piece of iron in the forge. Explain how the colour of the iron relates to its temperature. How does this relationship also apply to stars?
Question 76
2 marks · Easy
Answer and see the solution →Table: Star colour and temperature Star Surface temperature (K) Apparent colour X 6500 yellow Y 4000 red Z 32000 blue Which star in the table is classified as type O and which as type M? Explain your choices.
Question 77
2 marks · Easy
Answer and see the solution →Explain why two stars of different colours must have different surface temperatures.
Question 78
2 marks · Easy
Answer and see the solution →Table: Surface temperature and typical colour of some star classes Star class Surface temperature (K) Colour B 20,000 blue-white G 5,800 yellow K 4,600 orange M 3,200 red Which star class in the table has a surface temperature closest to the Sun? State the colour of this class.
Question 79
1 mark · Easy
Answer and check →Which statement describes the position of the Solar System within the Milky Way galaxy?
- A.At the centre of the galaxy
- B.Near the centre on a spiral arm
- C.About two-thirds out from the centre on a spiral arm
- D.Far outside the galaxy
Question 80
5 marks · Normal
Answer and see the solution →The table below shows the classification of some stars by their surface temperature and colour:
Star classification by temperature and colour Star class Surface temperature (K) Colour O more than 33 000 blue B 33 000 – 10 000 blue-white A 10 000 – 7 500 white G 6 000 – 5 200 yellow K 5 200 – 3 700 orange M 3 700 – 2 000 red (a)[1 mark]In which class would the Sun be placed? Give the class letter and colour.
(b)[2 marks]A star shines with a yellow-white colour. Estimate its surface temperature range using the table.
(c)[2 marks]Explain why a star that appears red is much cooler than a star that appears white.