Grade 7 · Science · Unit 3 of 9
Gravity & Tides
A pull that holds the Moon, planets and oceans
What your child practises
Children learn that gravity is a pull between objects, tell mass from weight, and see how the Moon’s gravity causes ocean tides.
Manitoba Curriculum learning outcome: SCI.7.E.4, SCI.7.E.5, SCI.7.E.6, SCI.7.E.7 · gravity, weight and mass, orbits, and tides
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
As two objects move farther apart, the gravitational pull between them…
- stops right away
- stays the same
- gets stronger
- gets weaker
Show answer
gets weaker
Hint: Gravity decreases with distance.
Question 2
Which force keeps you on the ground?
- magnetism
- gravity
- static electricity
- friction
Show answer
gravity
Hint: Earth’s gravity pulls you toward its centre.
Question 3
Which is the main force that holds the Solar System together?
- gravity
- sound
- magnetism
- friction
Show answer
gravity
Hint: The Sun’s gravity keeps the planets in orbit.
Question 4
Weight is measured in…
- metres
- litres
- kilograms
- newtons
Show answer
newtons
Hint: A newton (N) is the unit of force.
Question 5
The Moon orbits Earth because…
- Mars pulls it
- the Sun’s light pushes it
- Earth’s gravity pulls on it
- it is lighter than air
Show answer
Earth’s gravity pulls on it
Hint: Gravity keeps the Moon curving around Earth.
Question 6
A satellite orbits Earth. What would it do if gravity suddenly stopped?
- stop moving
- fall straight down
- speed up in a circle
- fly off in a straight line
Show answer
fly off in a straight line
Hint: Gravity bends its path. Without it, the satellite would go straight.