Gravity acts between masses and the gravitational field strength on Earth is about 10 N/kg, so this Year 8 sheet opens with the force's cause and its surface strength. The answers record Mercury as the closest planet and the Moon's low gravity from its lower mass.
Key Takeaways
Gravity acts between masses (Q1).
The Earth's gravitational field strength is about 10 N/kg (Q2).
Q3 records Mercury as the closest planet.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.Gravity is a force of attraction that acts between
(a) masses(b) electric charges(c) magnets(d) chemicals
2.The gravitational field strength on Earth is approximately
(a) 10 N/kg(b) 1 N/kg(c) 100 N/kg(d) 0.1 N/kg
3.Which planet is closest to the Sun?
(a) Mercury(b) Earth(c) Venus(d) Mars
4.Weight is a force that is measured in
(a) newtons(b) kilograms(c) grams(d) joules
5.The force of gravity on the Moon is weaker than on Earth because
(a) the Moon has less mass(b) the Moon is closer to the Sun(c) the Moon is made of gas(d) the Moon has no atmosphere
6.Which planet is furthest from the Sun?
(a) Neptune(b) Saturn(c) Uranus(d) Mars
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.Define gravity.
8.What is the difference between mass and weight?
9.State the value of the gravitational field strength on Earth.
10.Name the planet closest to and the planet furthest from the Sun.
11.Why does an astronaut weigh less on the Moon?
12.In what units are weight and mass measured?
13.How does the gravitational force between two objects change as the distance between them increases?
14.Write the formula for weight.
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.A 10 kg object is on Earth where g = 10 N/kg. Using W = m × g, find its weight.
16.A 60 kg astronaut stands on the Moon where g = 1.6 N/kg. Using W = m × g, find his weight there.
17.An object has a weight of 50 N on Earth where g = 10 N/kg. Using m = W ÷ g, find its mass.
18.The gravitational field strength on Mars is 3.8 N/kg. A rock has a mass of 2 kg. Using W = m × g, find its weight on Mars.
19.A 500 g mass is on Earth where g = 10 N/kg. First convert the mass to kilograms, then find its weight.
20.On Jupiter, g = 24 N/kg. A probe of mass 50 kg lands there. Using W = m × g, find its weight.
Answer Key
1. a) masses
2. a) 10 N/kg
3. a) Mercury
4. a) newtons
5. a) the Moon has less mass
6. a) Neptune
7. Refer to solution guide.
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20. Refer to solution guide.
End of Worksheet
People Also Ask
What does gravity act between?
Masses, option (a) in this worksheet (Q1).
What is the gravitational field strength on Earth?
About 10 N/kg, option (a) in this worksheet (Q2).
Why is gravity weaker on the Moon?
The Moon has less mass, option (a) in this worksheet (Q5).
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