Gravity KS2
What Is Gravity and How Does It Work?
Gravity is one of the forces that shapes our everyday lives, keeping our feet on the ground, making objects fall and holding the planets in orbit around the Sun. This guide explains gravity for KS2 children, including how gravity works, the effects of gravity and the discoveries of Sir Isaac Newton.
Need a KS2 gravity lesson?
Our ready-to-teach lesson pack contains everything you need to deliver a confident gravity lesson without the need to spend hours on planning. The pack contains:
- a detailed lesson plan
- teaching slides for the whole-class input
- practical activities
- differentiated printable resources
What is gravity?
Gravity is a force that pulls objects with mass towards one another. It acts over a distance, which means that objects do not need to be touching for gravity to affect them.
Every object with mass has its own gravitational pull. This includes planets, stars, people, animals and everyday objects. However, the gravitational pull of a small object is far too weak for us to notice.
The Earth has an enormous mass, so it has a much stronger gravitational pull. Earth's gravity pulls people and objects towards the centre of the planet. This is why we remain on the ground instead of floating into space.
Explaining gravity to a child
A simple way to explain gravity to a child is to describe it as an invisible pulling force.
Gravity is an invisible force that pulls things towards each other. The Earth is very large, so its gravity pulls us and other objects towards the ground.
Ask children to hold a pencil or rubber in the air and then let go. The object falls because the Earth is pulling it downwards. Although we often say that gravity pulls objects “down”, it is more accurate to say that gravity pulls them towards the centre of the Earth.
How does gravity work?
The strength of the gravitational force between two objects depends mainly on two things:
- The mass of the objects: objects with more mass produce a stronger gravitational pull.
- The distance between the objects: gravity becomes weaker as the distance between two objects increases.
Earth has enough mass to create a strong gravitational pull. When you jump into the air, you briefly move away from the ground, but Earth's gravity quickly pulls you back towards it.
Gravity also acts between the Earth and the Moon. Earth's gravitational pull helps to keep the Moon moving in orbit around our planet. In a similar way, the gravity of the Sun helps to keep Earth and the other planets in orbit around it.
What is Earth's gravitational pull?
Earth's gravitational pull is the force of attraction between the Earth and other objects with mass.
The Earth pulls objects towards its centre. At the same time, those objects also exert a tiny gravitational pull on the Earth. However, because the Earth has vastly more mass than an everyday object, the movement of the Earth is too small for us to notice.
Earth's gravitational pull:
- keeps people, animals and objects on the ground
- causes unsupported objects to fall
- gives objects weight
- helps to hold the atmosphere around the Earth
- helps to keep the Moon in orbit
What are the effects of gravity?
Children can observe the effects of gravity throughout their everyday lives. Gravity affects objects whether they are moving or stationary.
Gravity makes unsupported objects fall
If an object is not supported by a surface or another force, gravity causes it to accelerate towards the Earth. A ball released from someone's hand, for example, will fall towards the ground.
Gravity gives objects weight
Mass and weight are related, but they are not the same thing. Mass is the amount of matter in an object and is usually measured in kilograms. Weight is the force caused by gravity acting on that mass and is measured in newtons.
Gravity keeps planets and moons in orbit
Without gravity, the Moon would not remain in orbit around Earth and the planets would not remain in orbit around the Sun. Gravity continually pulls orbiting objects towards the larger body they are travelling around.
Gravity affects movement
When an object is thrown upwards, gravity pulls against its upward movement. The object slows down, briefly stops and then begins falling back towards Earth.
Do heavy objects fall faster than light objects?
A common misconception is that heavy objects always fall faster than light objects. If air resistance is removed, objects close to the Earth's surface accelerate at the same rate regardless of their mass.
In an ordinary classroom, however, air resistance can make objects appear to fall at different speeds. A flat sheet of paper falls more slowly than a compact ball of paper because the flat sheet has a larger surface area and experiences more air resistance.
This makes dropping different objects a useful KS2 investigation. Children can consider whether differences in falling time are caused by gravity, air resistance, the shape of the object or its surface area.
Who discovered gravity?
Sir Isaac Newton is often described as the scientist who discovered gravity. However, people were aware that objects fell long before Newton was born. Newton's achievement was developing a mathematical explanation for how gravity acts between objects.
In 1687, Newton published his law of universal gravitation. His work explained that every object with mass attracts every other object with mass. It also showed that the strength of this attraction depends on the objects' masses and the distance between them.
Did an apple really fall on Isaac Newton's head?
The famous story says that Newton began thinking about gravity after an apple fell from a tree. There is evidence that Newton told a story about watching an apple fall, but there is no reliable evidence that the apple struck him on the head.
The important part of the story is the question Newton considered: if the Earth pulls an apple towards the ground, could the same force extend much further and help to keep the Moon in orbit?
Gravity in the KS2 National Curriculum
Gravity is taught as part of the Year 5 Forces programme of study in the English National Curriculum.
Pupils should learn to explain that unsupported objects fall towards the Earth because of the force of gravity acting between the Earth and the falling object.
Children may explore this objective by:dropping and comparing different objects
- investigating the effects of air resistance
- identifying forces using arrows in diagrams
- distinguishing between mass and weight
- researching the work of scientists such as Isaac Newton and Galileo Galilei
- asking scientific questions and recording investigation results
Gravity KS2 PowerPoint, Lesson Plan and Activities
Teach your Year 5 class about the force of gravity with this complete, ready-to-teach lesson from PlanBee's Forces in Action scheme of work.
Children explore the effects of gravity and investigate how falling objects of different sizes are affected. They can then carry out a gravity experiment or use a range of sources to learn about scientists whose work helped to develop our understanding of gravity.
The Gravity KS2 lesson includes:
- a detailed lesson plan
- Gravity KS2 presentation slides
- activity ideas
- differentiated worksheets
- challenge cards
Simple gravity activities for KS2
Drop two objects
Choose two classroom objects and predict which will reach the floor first. Drop them from the same height at the same time and discuss whether the results support the prediction.
Paper drop investigation
Drop a flat sheet of paper and a tightly crumpled sheet of paper from the same height. Both have the same mass, but they fall differently because their shapes experience different amounts of air resistance.
Gravity force diagrams
Ask children to draw objects such as a falling apple, a parachutist or a ball being thrown upwards. They can add labelled arrows to show the direction in which gravity is acting.
Mass and weight comparison
Compare the mass and weight of an imaginary astronaut on Earth and on the Moon. The astronaut's mass remains the same, but their weight changes because the Moon has a weaker gravitational pull.
Gravity facts for kids
- Gravity is an attractive force, which means it pulls objects together.
- Anything with mass produces gravity.
- The greater an object's mass, the stronger its gravitational pull.
- Gravity becomes weaker as the distance between objects increases.
- Gravity pulls objects towards the centre of the Earth.
- Gravity keeps the Moon in orbit around Earth.
- The Sun's gravity helps to keep the planets in orbit.
- An object's mass stays the same on different planets, but its weight can change.
- Objects fall at the same rate in a vacuum, where there is no air resistance.
- Newton published his theory of universal gravitation in 1687.
Frequently Asked Questions about Gravity
What is gravity for kids?
Gravity is an invisible force that pulls objects with mass towards one another. Earth's gravity pulls people and objects towards the centre of the planet, which keeps us on the ground and makes unsupported objects fall.
How do you explain gravity to a child?
Describe gravity as an invisible pulling force. When a child drops a ball, the ball falls because the Earth is pulling it towards its centre. The Earth has a strong gravitational pull because it has a very large mass.
Who discovered gravity?
Sir Isaac Newton is often said to have discovered gravity. He did not discover that objects fall, but he developed a mathematical theory explaining that objects with mass attract one another. He published his law of universal gravitation in 1687.
Why do objects fall to the ground?
Unsupported objects fall because the force of gravity acts between the object and the Earth. Earth's gravity pulls the object towards the centre of the planet.
Does gravity only exist on Earth?
No. Anything with mass has gravity. The Moon, Sun, planets, stars, people and everyday objects all have gravitational pulls. Larger objects such as planets and stars have much stronger gravitational effects.
Is there gravity in space?
Yes. Gravity exists throughout space. Astronauts appear weightless because they and their spacecraft are continuously falling around the Earth while travelling in orbit, rather than because there is no gravity.
What is the difference between mass and weight?
Mass is the amount of matter in an object and is measured in kilograms. Weight is the force of gravity acting on an object's mass and is measured in newtons. An object's mass remains the same on the Moon, but its weight is lower because the Moon's gravitational pull is weaker.
When is gravity taught in KS2?
Gravity is included in the Year 5 Forces programme of study. Children learn that unsupported objects fall towards Earth because of the force of gravity acting between the Earth and the falling object.
