The Earth, Moon and SunIB MYP Physics: Subtopic test

1. 1
   A student in Reykjavik, Iceland, notices that in June the Sun stays above the horizon for about 21 hours each day, but in December it is up for only about 4 hours. Reykjavik is in the northern hemisphere.

   (a)

   What causes day and night on Earth?

   [1 mark]

   • AThe Earth orbiting the Sun once every year
   • BThe Sun moving around a stationary Earth
   • CThe Earth rotating on its axis once every 24 hours
   • DThe Moon blocking the Sun's light each day

   (b)

   What is the main reason for the different lengths of daylight in June and December?

   [1 mark]

   • AThe tilt of the Earth's axis as it orbits the Sun
   • BThe Earth is much closer to the Sun in June than in December
   • CThe Earth speeds up and slows down as it rotates
   • DThe Sun gives out more energy in June than in December

   (c)

   Explain why Reykjavik has much more daylight in June than in December.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Astronomers at an observatory in Chile record the appearance of the Moon every night. Over about 29.5 days its visible shape changes from a thin crescent to a full circle and back again. They also note that half of the Moon is always lit by the Sun.

   (a)

   What causes the phases of the Moon?

   [1 mark]

   • AThe Earth's shadow covers different parts of the Moon each night
   • BThe Moon gives out more or less of its own light
   • CThe Moon's shape physically changes as it orbits
   • DWe see different amounts of the Moon's lit half as it orbits the Earth

   (b)

   At new Moon, where is the Moon and which side faces the Earth?

   [1 mark]

   • ABeyond the Earth, with its lit side facing the Earth
   • BBetween the Earth and the Sun, with its unlit side facing the Earth
   • CBetween the Earth and the Sun, with its lit side facing the Earth
   • DInside the Earth's shadow, with no sunlight reaching it

   (c)

   Explain why half of the Moon is always lit but the shape we see changes over the month.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A total solar eclipse is predicted to cross parts of Indonesia. About two weeks later, a total lunar eclipse will be visible across Africa and Europe. Eclipses do not happen every month, even though the Moon orbits the Earth about once a month.

   (a)

   Describe how a solar eclipse happens.

   [3 marks]

   (b)

   Explain why a lunar eclipse is not seen every month.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A school in Nova Scotia, Canada, measures the water level in a harbour every hour for 30 days. The level rises and falls about twice a day. The difference between high and low water is largest around the time of full Moon and new Moon, and smallest around the half Moons. A company has proposed building a tidal power scheme across the bay, and local people are debating it.

   (a)

   A student wants to repeat the investigation. State a testable hypothesis, with a scientific reason, linking the size of the tides to the phase of the Moon. Identify the independent and dependent variables, outline how the data should be collected, and suggest one way to improve reliability.

   [6 marks]

   (b)

   Discuss and evaluate whether the tidal power scheme should be built.

   [6 marks]

   Total for question 4: 12 marks

End of questions