New
New
Year 7

Gravity

I can describe the effects of gravity acting towards the centre of a nearby planet, moon or star.

New
New
Year 7

Gravity

I can describe the effects of gravity acting towards the centre of a nearby planet, moon or star.

Lesson details

Key learning points

  1. Gravitational forces pull (attract) objects towards the centre of large objects like planets, moons and stars.
  2. The greater the mass of an object, the stronger its gravity.
  3. The gravity of a planet, moon or star extends far into space, but gets weaker with distance.
  4. Earth’s gravity pulls the Moon towards the centre of Earth, changing the Moon's direction, making it orbit around Earth.
  5. The Sun's gravity pulls Earth towards the centre of the Sun, changing Earth's direction, making it orbit around the Sun.

Common misconception

There is no gravity in space, even a short distance from the Earth.

Carefully whirl a rubber bung around your head on a length of string to show how force of a string keeps it orbiting in a circle, just as the force of gravity keeps the Moon orbiting the Earth and the planets orbiting the Sun.

Keywords

  • Gravitational force - Gravitational forces pull objects towards large objects like planets, moons and stars.

  • Attraction - An attraction is a force that acts to pull one object towards another.

  • Orbit - An orbit is the movement of one object in a loop around another object.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is the name of the force that pulls objects towards the ground?
magnetic force
Correct answer: gravitational force
friction
upthrust
Q2.
In which direction will a ball move if you pick it up and then release it above the ground?
The ball will not move.
The ball will move upwards.
The ball will move left-to-right.
Correct answer: The ball will move downwards.
Q3.
Which scientist is thought to have discovered the existence of gravity after seeing an apple fall from a tree in their garden?
Marie Curie
Albert Einstein
Correct answer: Sir Isaac Newton
Robert Hooke
Q4.
Where would you feel the strongest gravitational force of attraction from Earth?
On the International Space Station.
At the top of Mount Everest.
On the surface of the Moon.
Correct answer: At sea level.
Q5.
Which planet has the strongest gravitational field?
Venus
Earth
Correct answer: Jupiter
Mercury
Q6.
Put these pairs of orbiting objects in order of increasing gravitational force between them, starting with the smallest.
1 - A communications satellite orbiting Earth.
2 - The Moon orbiting Earth.
3 - Earth orbiting the Sun.
4 - The Sun orbiting the centre of the Milky Way galaxy.

6 Questions

Q1.
Which of these statements about the gravitational force from one object acting on another is correct?
Correct answer: It is a non-contact force.
It causes attraction and repulsion.
It stops acting when an object is falling.
It does not act on objects in space.
Q2.
Why does the person shown on the southern hemisphere of Earth not fall off?
An image in a quiz
Correct answer: Earth's gravitational force acts towards the centre of the planet.
Earth's gravitational force on the person acts downwards.
The Moon's gravitational force pushes the person toward Earth's surface.
Other forces, such as magnetic forces, hold them in place.
Q3.
Put these objects in order of increasing gravitational field strength, starting with the smallest.
1 - Earth's Moon
2 - Earth
3 - Jupiter
4 - the Sun
Q4.
The photo shows an astronaut on the Moon with a flag. Why does the flag not droop towards the surface of the Moon?
An image in a quiz
Correct answer: The gravitational force on the Moon's surface is much less than it is on Earth.
There is no gravity on the Moon's surface to pull the flag down.
There is a breeze on the Moon which is blowing the flag to the left.
On the Moon, gravitational forces are repulsive, not attractive.
Q5.
Where would you feel the strongest gravitational force of attraction from Earth?
Correct answer: On the surface of Earth.
At the top of a mountain.
At the altitude that communications satellites orbit Earth.
At the mid-point between the Moon and Earth.
Q6.
Which of these statements about gravitational forces is correct?
Correct answer: A gravitational force acts between all object with mass.
A gravitational force can only attract metals and only repel non-metals.
A gravitational force only exists between solid objects.
The gravitational force of a spinning planet causes it to become flat.

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