Forces Made Easy: PSLE Science Guide for Primary 6 Students

What is a Force?

A force is just a push or a pull.
You use forces every day — opening a door, kicking a ball, or zipping your bag.

Forces can:

• Start something moving 🏃
• Stop something moving ✋
• Make it move faster or slower ⏩⏪
• Change its direction ↩️
• Change its shape 🛠️

1. Frictional Force: The Slowing Force

What it is:
Friction happens when two surfaces rub against each other.

Key things to remember (and avoid mistakes!):

• Rough surface → more friction (carpet)
• Smooth surface → less friction (tiles)
• Friction can slow things down but can also help you grip (shoes on the floor).
  ❌ Misconception: Friction is always bad — but without it, you would slip when walking!

That’s why you can slide faster on a smooth floor than on a carpet!

Try it: Rub your hands fast — that heat is friction at work.

2. Elastic Spring Force: The Force That Bounces Back

What it is:
When you stretch or compress a spring, elastic spring force tries to return it to its original shape.

Key points to remember:

• The more you stretch or compress → the greater the elastic spring force
• This force acts in the opposite direction of the stretch or compression
• Works in things like trampolines, pogo sticks, and spring scales

❌ Common Misconceptions:

• Thinking the force pushes in the same direction you stretch — actually, it pushes back.
• Believing only springs have elastic force — rubber bands and some materials can also show this force.

Example:
When you pull a rubber band and let go, it snaps back because of elastic spring force.

3. Gravitational Force: The Downward Pull

What it is:
Gravity pulls everything toward Earth.

Key things to remember (and avoid mistakes!):

• Keep us on the ground
• Make rain fall
• Bring a ball back down after you throw it up

❌ Misconception:
Gravity only works on Earth — it’s actually everywhere! It’s also why the Moon orbits Earth.

4. Magnetic Force: Pulling and Pushing Without Contact

What it is:
Magnetic force acts at a distance. You don’t need to touch an object for a magnet to pull it!

Rules to remember:

• Unlike poles (North + South) attract
• Like poles (North + North or South + South) repel
• Only certain materials are magnetic (iron, steel, nickel, cobalt)

❌ Misconception: All metals are magnetic — nope! Coins like aluminium are not.

Balanced and Unbalanced Forces: The Tug of War

When multiple forces act on an object:

• If they are equal (balanced forces), the object remains stationary or continues to move at a constant speed
• If they are unequal (unbalanced forces), the object moves / stops, speeds up / slows down, or changes direction

Think: Why does the rope move in tug-of-war? The side with more force wins!

Why This Matters for PSLE

• Knowing what each force does helps you answer OEQs quickly.
• Watch out for trick questions mixing up gravity and magnetism.
• Always link force → effect in your answer.

Quick Recap Table:

Force	What It Does	Example
Frictional Force	Slows down motion / helps grip	Shoes gripping the floor
Elastic Spring Force	Pulls stretched/compressed objects back to original shape	Rubber band snapping back
Gravitational Force	Pulls towards Earth	Ball falling
Magnetic Force	Attracts/repels at a distance	Fridge magnet

Ready to test your knowledge?
📥  Click here to download the Forces worksheet and try it now!

Includes:
✔️ Multiple Choice Questions
✔️ Fill in the Blanks
✔️ Match the Columns
✔️ Short Answers
✔️ Answer Sheet Provided!