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y13

Phy 5 2004

y10

Answers to questions set in lesson.


1 Mercury (as well as extreme heat), Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
2 Mercury and Venus have
temperatures greater than that on the Earth.
3 Jupiter, Saturn, Uranus and Neptune – because they are ‘gaseous’ planets.
4 Venus: The planet has a thick highpressure atmosphere (enough to crush us), very high temperatures and its atmosphere has clouds of
sulphuric acid (so the rain would be acid!).
5 Europa has evidence of water – which is essential for life.
6 Reduced fuel costs as there is less effort to escape a planet’s or moon’s gravitational pull. It would also be cheaper to re-supply the hotels too, for the same reason.
7 Open-ended research question.

y10

Homework Answers


H5 Centripetal force and the
solar system
1 Rocky/circular orbit/much smaller than a planet
(less than 1000 km).
Any two. 2
Total 2
2 (a) Ellipse. 1
(b) When it is near the Sun. 1
(c) Frozen ice and rock. 1
Total 3
3 (a) The force of gravity 1
between Mars and the Sun. 1
(b) The force of gravity 1
between the comet and the Sun. 1
(c) The force of gravity 1
between the Moon and Earth. 1
Total 6
4 (a) Centripetal. 1
(b) (i) The tension in the string. 1
(ii) Friction between tyre and road. 1
(iii) The gravitational force between the
satellite and Earth. 1
Total 4
5 (a) Arrow from centre of the Moon pointing towards
the centre of Earth labelled force of Earth on
the Moon. 1
Arrow from centre of Earth pointing towards the
centre of the Moon labelled force of the Moon
on Earth. 1
(b) Both forces have the same size 1
and act in opposite directions. 1
(c) Answers involving the idea that the two forces
are not acting on the same body (e.g. Earth only
experiences one of the forces, the Moon
experiences the other force only). 1
Total 5