The solar systemIB MYP Physics: Subtopic test

1. 1
   A museum in Cape Town is building a model of the solar system for visitors. The model includes the Sun, the eight planets, the dwarf planet Pluto, several moons and asteroids, and Halley's comet.

   (a)

   Which two planets in the model are gas giants?

   [1 mark]

   • AMercury and Venus
   • BEarth and Mars
   • CPluto and Ceres
   • DJupiter and Saturn

   (b)

   Which description best fits the orbit of Halley's comet?

   [1 mark]

   • AA nearly circular orbit around the Earth
   • BA very long, thin ellipse that takes it close to the Sun and then far beyond Neptune
   • CA nearly circular orbit between Mars and Jupiter
   • DA nearly circular orbit around Jupiter

   (c)

   State two differences between rocky planets and gas giants.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   An astronomer compares the time that planets take to orbit the Sun. Earth takes 1 year, Mars takes about 1.9 years, Jupiter takes about 11.9 years and Neptune takes about 165 years.

   (a)

   Which statement describes the pattern in the data?

   [1 mark]

   • AThe further a planet is from the Sun, the shorter its orbital period
   • BThe orbital period does not depend on the distance from the Sun
   • CThe further a planet is from the Sun, the longer its orbital period
   • DThe larger the planet, the longer its orbital period

   (b)

   Venus orbits closer to the Sun than the Earth. Which orbital period is Venus most likely to have?

   [1 mark]

   • AAbout 0.6 years
   • BAbout 1.0 year
   • CAbout 1.9 years
   • DAbout 11.9 years

   (c)

   Explain why Neptune takes much longer than Mars to orbit the Sun.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A telecommunications company in Nigeria plans to launch a satellite to broadcast television signals to the whole country. A weather agency already operates a different satellite that orbits about 800 km above the Earth and completes about 14 orbits every day.

   (a)

   Describe the orbit of a geostationary satellite.

   [3 marks]

   (b)

   Explain why a geostationary orbit suits the television satellite, but a low orbit suits the weather satellite.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A class researches planetary data published by a space agency. Mercury is 0.39 astronomical units (AU) from the Sun and takes 0.24 years to orbit it. Earth is 1.00 AU away and takes 1.00 years. Jupiter is 5.2 AU away and takes 11.9 years. Saturn is 9.5 AU away and takes 29.5 years. A student suggests that the orbital period is directly proportional to the distance from the Sun. The class also reads a proposal to spend public money on a crewed mission to Mars instead of more robotic probes.

   (a)

   Describe the trend in the data. Use the data for the Earth and Saturn to test the student's suggestion, and evaluate it, giving a scientific reason for the pattern.

   [6 marks]

   (b)

   Discuss and evaluate whether public money should be spent on a crewed mission to Mars instead of more robotic probes.

   [6 marks]

   Total for question 4: 12 marks

End of questions