Gravity on other
planets
9Jb/2
Name
Class
Some planets have stronger gravity than others. Gravity depends on the size of the
planet. On Earth, gravity pulls on every kilogram with a force of 10 newtons.
You can work out the weight of something if you know its mass and the strength of
gravity. The strength of gravity is 10 N/kg on Earth, but only 1.6 N/kg on the Moon.
weight (N) = mass (kg) × strength of gravity (N/kg)
?
1 Work out the weights of these objects on the Earth and on the Moon.
Object
Mass (kg)
hammer
1
box of books
12
oxygen cylinder
20
box of food
8
Weight on Earth (N)
Weight on the Moon (N)
2 Imagine that you had to move the things in question 1 around on the Moon.
a In what way would it be easier to move them on the Moon than on
the Earth?
b In what way might it be more difficult?
3 Now work out what your weight would be on other planets if your mass is
40 kg. Write your answers in the table. Saturn has been done for you.
Planet
Gravity (N per kg)
Mass (kg)
Mercury
3
40
Venus
9
40
Earth
10
40
Mars
4
40
Jupiter
23
40
Saturn
9
40
Uranus
8
40
Neptune
11
40
Pluto
S
0.4
Weight (N)
360
40
knowledge, numeracy
Exploring Science for QCA
Copymaster File 9
521
© Pearson Education Limited 2002
9
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