C. Matter and Energy · Forces Causing Movement

Ways to Exert a Force

C2.2 A1.5About 30 minutes

Learning goals

I can describe many ways to exert (put) a force on an object: push, pull, lift, throw, kick, hit, squeeze, stretch, twist and bend.
I can explain that a force can be exerted directly by my body or through a tool, a rope, an animal, a machine or nature.
I can explain tension (a pull through a rope) and compression (a squeeze).
I can describe forces clearly using science words.

Words to know

exert
To put a force on something.

squeeze (compress)
To push in on something from two sides so it gets smaller. This is called compression.

stretch
To pull on something from two ends so it gets longer.

twist
To turn one part of an object, like turning a jar lid.

bend
To push or pull on something so it curves, like a fishing rod.

tension
The pulling force in a rope, string or chain that is pulled tight.

So many ways!

Think about everything you did this morning. You pulled up your covers, twisted the tap, squeezed the toothpaste, pushed your arms into your sleeves and lifted your backpack.

Each of these actions exerts a force. To exert a force means to put a push or a pull on something.

Ways to exert a force

All forces are pushes or pulls, but we exert them in many ways:

Push or press: push a door, press a button.
Pull: pull a zipper, pull a wagon.
Lift: pick up a basket (you push it upward).
Throw, kick or hit: throw a ball, kick a soccer ball, hit a puck with a stick.
Squeeze (compress): squeeze a sponge or a snowball.
Stretch: stretch an elastic band.
Twist: twist a jar lid or a doorknob.
Bend: bend a pipe cleaner or a straw.

A table with a jar of jam and its lid, a sponge, a tube, a small red wagon and a backpack with an open zipper. — Each object needs a different action: twist the jar lid, squeeze the sponge or tube, pull the wagon handle and pull the zipper. Every one is a push or a pull. AI-generated image

Three ways to exert a force. Squeeze: push in from both sides. Stretch: pull out from both ends. Twist: turn it around.

Who or what exerts the force?

A force can be exerted:

Directly by your body: your hands, feet, shoulders or head.
Through a tool: a hockey stick hits a puck, a broom pushes snow, a spoon stirs soup.
Through a rope or chain: when you pull a rope tight, a pulling force goes all along it. This pull is called tension. In tug-of-war, the tension in the rope pulls on both teams.
By animals: a horse pulls a wagon, sled dogs pull a sled.
By machines: a snowplow pushes snow, a crane lifts steel beams.
By nature: wind pushes a sailboat, a river pushes a canoe downstream, gravity pulls rain down.
Without touching: a magnet pulls a paper clip.

Action	Push or pull?	Who or what exerts it?
kicking a soccer ball	push	your foot (directly)
hitting a puck	push	a hockey stick (a tool)
tug-of-war	pull	people, through a rope (tension)
squeezing a snowball	push (from all sides)	your hands
stretching an elastic band	pull (from both ends)	your fingers
a sailboat moving	push	the wind (nature)

Describing how a force is exerted

Worked example

Let's describe the forces in building a snowman

Describe the ways forces are exerted to build a snowman.

Squeeze (compress) a handful of snow to start a ball.
Push the ball so it rolls across the yard and gets bigger.
Lift the middle ball up onto the big bottom ball. That is an upward push from your arms.
Press snow into the cracks so the balls stay together.
Twist a carrot nose into place.
Gravity pulls the balls down, which helps hold the snowman together on the ground.

Squeeze, push, lift, press and twist are all ways you exert forces. Gravity also exerts a force, pulling the snowman down.

Describing a force like a scientist

A clear description answers three questions:

What kind of push or pull is it? (squeeze, twist, kick...)
What exerts it? (my hands, a rope, the wind...)
Which way does it act? (up, down, toward, away)

Example: "My foot exerts a push on the ball, away from me."

Describing a kick like a scientist: say what kind of force, what exerts it, and which way it acts.

Just for fun

What did the sponge say after a really big squeeze?

"Wow, I feel completely drained!"

Hands-on activity

Force station

You need: play dough or modelling clay (or bread dough), an elastic band, a sponge, a pipe cleaner or a bendy straw, a jar with a lid, and a small ball.

Use the play dough to show each way to exert a force: push, pull, squeeze, stretch, twist and bend. Say the word out loud as you do it.
Squeeze the sponge. Stretch the elastic band (gently, pointed away from faces). Bend the pipe cleaner. Twist the jar lid.
Throw, roll and lift the ball.
Make a chart: Object, What I did, Push or pull?
Share: pick three actions and describe each one with the three questions: What kind? What exerts it? Which way?

What to look for: your child names the action correctly and can say whether it is a push or a pull (squeezing and pressing are pushes; stretching is a pull; twisting turns the object).

Safety: do not stretch elastic bands near faces or let them snap.

Your turn

What does "exert a force" mean?

Name four ways to exert a force with your hands.

Is stretching an elastic band a push or a pull?

Is squeezing a sponge a push or a pull?

What is tension?

A hockey stick hits a puck. Is the force exerted directly by your body or through a tool?

Name a force exerted by nature.

More practice: warm-up

Is opening a jar lid a twist or a stretch?

Is pressing an elevator button a push or a pull?

What do you do to a snowball to pack it tight?

Name an animal that can exert a pulling force.

In tug-of-war, what is the pull in the rope called?

More practice: on your own

Describe the force when you kick a ball, using the three questions (What kind? What exerts it? Which way?).

A snowplow clears the road. What kind of force does it exert, and what exerts it?

Give an example of a force exerted through a rope.

You bend a straw and it stays bent. You bend a ruler a little and it springs back. Did you exert a force both times?

Sort these into push or pull: kick, squeeze, stretch, lift, pull a drawer, press a doorbell.

Challenge

Wind can exert a force on a kite, and so can you. Describe both forces on a flying kite, and say which way each one acts.

Think of a game of tug-of-war. Team A pulls left and Team B pulls right. Describe how each team exerts its force, and what happens if Team B pulls harder.

Make up your own example for each one: a force exerted by your body, by a tool, by a machine, and by nature.

Check your understanding

Quiz

To exert a force means to...

Which action is a squeeze?

Stretching an elastic band is a...

The pulling force in a rope pulled tight is called...

A broom pushes snow off the steps. The force is exerted...

Which is a force exerted by nature?

For parents and teachers

Big idea: Ontario Grade 3 expectation C2.2 asks children to describe different ways a force can be exerted on an object: pushing, pulling, lifting, throwing, kicking, hitting, squeezing, stretching, twisting and bending, whether directly by the body, through a tool or rope (tension), by animals or machines, or by natural forces like wind and moving water. Describing forces with clear words (what kind, what exerts it, which way) is the communication skill in A1.5.

How to help: Narrate a routine together: "I'm twisting the lid... you're pulling the zipper." Ask your child to name the action and say if it's a push or a pull.

Common difficulties:

Thinking twisting or squeezing are not pushes or pulls. All forces are pushes or pulls; squeezing is pushing in, stretching is pulling out, twisting is pushing one side and pulling the other.
Forgetting non-human forces. Wind, water, animals and machines exert forces too.
Vague descriptions. Encourage the three-question sentence.

Safety: keep elastic bands away from faces.