Forces & MotionGrade 3 Science for Kids

Balanced and unbalanced forces, friction and how mass changes motion.

Forces & Motion helps third graders find out why things start, stop and change direction. Kids explore balanced and unbalanced forces, test friction on different floors and see why a heavier cart is harder to push.

  • Grade 3 · Ages 8–9
  • 3 lessons
  • 3 experiments
  • 12 practice questions
  • About 25 min
Start Learning Free Open the Course
  • Balanced and Unbalanced
  • Moving or Not?
  • Friction
  • Slide Test
  • Mass and Motion
  • Cargo Cart

Science lab course · Grade 3

Forces & Motion · Learning goals

What Your Child Will Learn

Find out why things start, stop and change direction. Test friction on different floors and see how a heavier cart is harder to push.

  • Balanced forces don't change motion. Unbalanced forces start, stop or turn things.
  • Friction slows moving things. Smooth surfaces have less friction than rough ones.
  • The more mass something has, the bigger the force needed to move it.

Why it matters

Why This Matters for Kids

  • Physics basics

    Forces and motion is a core grade 3 science topic and the start of physics.

  • Friction in life

    Friction explains why shoes grip, why we slip on ice and why brakes work.

  • Predicting motion

    Understanding forces helps kids predict how things will move, in sports and play.

Inside Forces & Motion

How the Course Works

Each level has a short read-aloud lesson, an interactive experiment and a mini quiz.

  1. Step 1 · Lesson

    Balanced and Unbalanced

    A force is a push or a pull. Every force has a size and a direction.

  2. Step 2 · Experiment

    Moving or Not?

    Let's look at forces in action. Are the forces balanced or unbalanced in each case?

  3. Step 3 · Lesson

    Friction

    Friction is a force that slows things down when surfaces rub together.

  4. Step 4 · Experiment

    Slide Test

    Let's push a toy car with the same push on four different floors and measure how far it goes.

  5. Step 5 · Lesson

    Mass and Motion

    Mass is how much matter something has. More mass usually means heavier.

  6. Step 6 · Experiment

    Cargo Cart

    Let's give a toy cart the same push each time, but add more books inside. How far will it roll?

Lesson preview

A Peek Inside the Lesson

This is the real lesson text your child hears, read aloud by a friendly voice.

Balanced and Unbalanced

A force is a push or a pull. Every force has a size and a direction.

When forces are balanced, they cancel out. Nothing changes: a still thing stays still.

When forces are unbalanced, things start moving, speed up, slow down or turn.

In tug of war, the stronger team makes the forces unbalanced and wins!

Friction

Friction is a force that slows things down when surfaces rub together.

Rough surfaces like carpet and sand make lots of friction.

Smooth surfaces like ice make little friction. Things slide far!

Friction is useful too: it stops our shoes from slipping.

Mass and Motion

Mass is how much matter something has. More mass usually means heavier.

It takes a bigger force to move something with more mass.

A full shopping cart is harder to start and harder to stop than an empty one!

For parents

Try It at Home

Learning sticks best when kids use it in real life. Here are simple ideas from this course.

Parent Tip

Slide a toy car across carpet, tile and a towel. Ask your child which surface has the most friction and why.

Moving or Not?

  1. Put a toy car on a table.
  2. Push it gently from both sides with the same force. Does it move?
  3. Now push harder from one side!

Balanced forces don't change motion. Unbalanced forces start, stop or turn things.

Slide Test

  1. Make a ramp with a book.
  2. Let a toy car roll onto wood, a towel and foil.
  3. Measure how far it rolls each time.

Friction slows moving things. Smooth surfaces have less friction than rough ones.

Cargo Cart

  1. Tie a string to a toy truck.
  2. Pull it with a rubber band and watch how far the band stretches.
  3. Add toys to the truck. Does the band stretch more?

The more mass something has, the bigger the force needed to move it.

Practice

Grade 3 Science Practice Questions

Real questions from Forces & Motion. Try them with your child, then tap to see the answer.

  1. Question 1

    What is a force?

    • A.A push or a pull
    • B.A kind of energy drink
    • C.A color
    Show answer

    A push or a pull

  2. Question 2

    What does friction do?

    • A.Speeds things up
    • B.Slows moving things down
    • C.Makes things float
    Show answer

    Slows moving things down

  3. Question 3

    What is mass?

    • A.How fast it goes
    • B.Its color
    • C.How much matter something has
    Show answer

    How much matter something has

The full course has 12 questions with instant feedback, stars and rewards. Create a free account to play them all.

Forces & Motion · Questions from parents

Frequently Asked Questions

What age is this course for?

Forces & Motion is a grade 3 science course for kids ages 8–9. That is Year 4 science in the UK and Year 3 in Australia. It also works well for review in the next grade, or as a challenge for a confident younger learner.

What will my child learn?

Find out why things start, stop and change direction. Test friction on different floors and see how a heavier cart is harder to push. Along the way they practice: Balanced forces don't change motion. Unbalanced forces start, stop or turn things; Friction slows moving things. Smooth surfaces have less friction than rough ones; The more mass something has, the bigger the force needed to move it.

How long does the course take?

About 25 minutes in total, split into 3 short levels. Most kids finish it over two or three sessions. Progress is saved, so they can stop any time and pick up where they left off.

Is this course free?

Yes. Forces & Motion is one of the first 2 courses in Grade 3 Science. Create a free parent account and your child can start right away.

Does my child need to read well to use it?

No. Every lesson has a friendly read-aloud voice, questions are read aloud too, and the pictures help kids follow along. Confident readers can turn the voice off.

Can we use it for homeschool?

Yes. SkillBloom is built for homeschooling families. Kids work through lessons, games and quizzes on their own, and the parent dashboard shows what they finished and which skills need more practice. It works on phones, tablets and laptops.

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