Forces sound like a big science word, but young children use them all day: pushing a swing, pulling on socks, kicking a ball. In the first years of school they start to notice how pushes and pulls make things move, and why some things roll while others slide. Here are push and pull forces for kids in plain words, why round things roll and flat ones slide, what slows things down, and a ramp test you can set up with a pile of books.
What is a force?
A force is a push or a pull. The Victorian Curriculum puts it this way: “pushes and pulls are forces that can change an object’s movement or shape and can be represented in terms of strength and direction.” For young children, the simplest rule is:
- A push moves something away from you: kicking a ball, pushing a trolley, pressing piano keys.
- A pull brings something towards you: opening a drawer, pulling a carrot out of the ground, a dog tugging on its lead.
The curriculum suggests children look for forces in everyday things like “playground equipment, toys, windows and doors”. Next time you’re at the park, ask your child to spot the pushes and pulls.
What can a push or a pull do?
More than you might think. A push or pull can:
- start something moving, like a ball you kick
- stop it, like catching that ball
- change its direction, like hitting a ball back with a bat
- change its shape, like squashing or stretching playdough
The curriculum lists all four: pushing or pulling “can start or stop its motion, or change its direction of travel”, and children explore how “the shape of modelling dough can be changed when pushed or pulled”. Strength matters too. A small push makes a ball roll a little way. A bigger push makes it roll further.
Why do round things roll and flat things slide?
How something moves depends on its shape, size and what it’s made of. The Victorian Curriculum says “the way objects move depends on a variety of factors including their size, shape and material.”
Shape. A ball touches the ground at one small spot and simply turns over and over. A box sits flat on a whole side, so it has to scrape along the ground, and that rubbing holds it back. Give a ball and a box the same push and the ball goes further. Anything with a round, curved side can roll: a can on its side, a pencil, an orange, a wheel. That’s why wheels are round.
Material. Drop a rubber ball and it bounces back up. Drop a ball of playdough and it squashes flat and stays down. The curriculum suggests exploring how a ball made of “plastic, foam, cloth or rubber” changes the way it moves. It even mentions marngrook, a football game played by some Aboriginal groups, which “was traditionally played with a possum-skin ball in south-western Victoria”.
Why do rolling things slow down and stop?
Many children think a ball stops because it “runs out of push”. In fact, the ground and the air rub against it and slow it down. That rubbing force is called friction. Later in primary school, children learn “how friction causes objects to slow down and perhaps stop”.
Rough and soft surfaces rub more than smooth ones. That’s why a toy car zooms across a wooden floor but stops quickly on long grass, soft sand or a woolly rug, and why a ball rolls a long way on a smooth footpath.
And why do things roll down a ramp on their own? Gravity. The curriculum describes gravity as “the force that pulls all objects towards the centre of Earth”. On a slope, gravity pulls round things down and they roll. A flat block needs a steeper slope before gravity can beat the rubbing and make it slide.
Try the ramp test at home
You need a big book, a tray or a chopping board, a few other books, and some things to test: a ball, a toy car, a wooden block and an orange.
- Make a low ramp. Lean the big book or tray on a few other books, with a clear floor at the bottom.
- Guess first. Will each thing roll, slide or stay still?
- Let go. Put each thing at the top of the ramp and let go, without a push. Watch what it does.
- Record. Tick what happened next to each guess.
- Change one thing. Make the ramp a little steeper and try the block again. Or lay a towel at the bottom and compare how far the car rolls on it.
- Measure. Measure how far each thing travelled in handspans, blocks or pencil lengths, the kind of informal measuring the curriculum suggests.
| Thing | What it usually does | Why |
|---|---|---|
| Ball | Rolls | It’s round all over |
| Toy car | Rolls | Its wheels are round |
| Orange | Rolls | It has a round shape |
| Wooden block | Slides, or stays still if the ramp isn’t steep enough | Its flat sides rub on the ramp |
Keep the ramp low, and let things roll onto a clear floor away from stairs. Floating is about forces too (water pushes up on a boat), which makes our sink or float experiment a good next step, and there are more ideas in our kitchen science experiments.
What children learn about forces at school
Pushes and pulls are part of science from the first year of school. That year is called Foundation or Prep in Victoria, Prep in Queensland and Tasmania, Kindergarten in NSW and the ACT, Reception in South Australia, Pre-primary in WA (the first compulsory year there) and Transition in the Northern Territory.
In Victoria, children learn across Foundation to Year 2 that “the way objects move depends on a variety of factors including their size, shape and material” (VC2S2U10) and that “pushes and pulls are forces” (VC2S2U11). One example is “observing and describing movements of different and unusually shaped objects such as blocks, tubes and boiled eggs when rolled down a slope”. By the end of Year 2, children “describe and predict how different strengths and directions of pushes and pulls change the motion and shape of objects.” There’s more on the whole band in our post on what a Year 1 child should know.
In the Australian Curriculum (AC9), Foundation children “describe how objects move and how factors including their size, shape or material influence their movement” (AC9SFU02), and Year 1 children “describe pushes and pulls in terms of strength and direction and predict the effect of these forces on objects’ motion and shape” (AC9S1U03). Friction and gravity come later, in Year 4 (AC9S4U03).
KidStudy’s Year 1 Science lesson Roll, Slide and Bounce is about how shape and material change the way things move: round things roll and flat things slide, rough ground slows a toy car down, and a rubber ball bounces while playdough squashes. Its home activity is the ramp test above. The Prep lesson Push and Pull shows that pushes move things away, pulls bring them closer, and a bigger push makes a ball roll further.
Questions parents ask
What is a push and pull force for kids?
A force is a push or a pull. A push moves something away from you and a pull brings it towards you. Forces can start things moving, stop them, change their direction or change their shape.
What are some examples of push and pull?
Pushes: kicking a ball, pushing a trolley, pressing piano keys, ringing a bell. Pulls: opening a drawer, pulling a carrot out of the ground, walking a dog on a lead, pulling on socks.
Why do round things roll?
A round thing touches the ground at one small spot and turns over and over, so there’s little to hold it back. A flat-sided thing has to scrape along on a whole side, so it slides, or stays put if the slope isn’t steep enough.
What is friction for kids?
Friction is a rubbing force between two surfaces. It slows moving things down and can stop them. Rough surfaces like grass or carpet make more friction than smooth ones like a wooden floor.
Why does a ball stop rolling?
Not because it runs out of push. The ground and the air rub against it (friction) and slow it down, which is why a ball rolls further on a smooth floor than on grass.
Is gravity a push or a pull?
A pull. The curriculum describes gravity as the force that pulls all objects towards the centre of Earth. That’s why things roll down a ramp and fall when you drop them.
Sources
- Victorian Curriculum F–10 Version 2.0: Science, VCAA
- Australian Curriculum v9.0: Science, Foundation, ACARA
- Australian Curriculum v9.0: Science, Year 1, ACARA
- Australian Curriculum v9.0: Science, Year 4, ACARA
- School enrolment pages from each state and territory government: Victoria, NSW, Queensland, South Australia, Western Australia, Tasmania, Northern Territory and ACT
