How do action and reaction forces affect walking on ice?

In one line

The rule

For every action, there is an equal and opposite reaction.

The formula is: F₁ = −F₂ Where:

• F₁ is the action force (your foot pushes on the ice)
• F₂ is the reaction force (the ice pushes back on your foot, equally but in the opposite direction)

Let's understand it simply

Imagine you are walking on a dry road. When you push your foot backward against the ground, the ground pushes you forward. This is why you move ahead. Now, think about walking on a smooth, wet floor or ice. When you try to push back, your foot slips because the ice is very smooth and slippery.

The main idea: You move forward because the ground pushes you forward when you push it backward. On ice, your foot can't grip the surface well, so the push (action) is weak, and the reaction can't help you move forward easily.

How it works

1. You put your foot on the ice and try to push it backward (action force).
2. According to Newton's Third Law, the ice should push your foot forward (reaction force).
3. On normal ground, friction (the grip between your shoe and the ground) helps you push back strongly.
4. On ice, friction is very low. Your foot slides instead of pushing back hard.
5. Because the action force is weak or slips, the reaction force is also weak or in the wrong direction.
6. As a result, you may not move forward well or you may slip and fall.

The story behind it

Newton's Third Law was described by Sir Isaac Newton in 1687 in his famous book, the Principia. He noticed that forces always come in pairs. He was trying to explain why things move or stay still, like why a boat moves forward when you row it backward. Newton's laws are now the base of all mechanics (the study of motion).

Where you see it in real life

• Walking on a dry road: Your foot pushes back, the ground pushes you forward → you walk easily.
• Walking on ice: Your foot slips, so you can't push back well → you struggle to move forward.
• Cricket bowler's run-up: The bowler pushes the ground backward, the ground pushes him forward → fast run-up.
• Rowing a boat: Oar pushes water backward (action), water pushes boat forward (reaction).
• Jumping off a bus step: You push down and back, the step pushes you up and forward.
• Cycling: Pedal pushes the road backward, road pushes cycle forward.

Why it matters

• Safety: Knowing this helps you avoid slipping on ice or wet floors.
• Sports: Runners, footballers, and cricketers use this idea to move faster.
• Engineering: Designing shoes with better grip for slippery surfaces.
• Physics exams: Newton's laws are the base for many questions and future chapters.

Worked example

Let's see what happens if you try to walk on ice:

Given: Weight of student = 50 kg
Step 1: Student tries to push ice backward with foot (action force)
Step 2: Ice should push student forward (reaction force)
Step 3: On dry ground, friction = high, so action and reaction are strong → student moves forward
Step 4: On ice, friction = very low, so action and reaction are weak → student slips or cannot move forward well
Step 5: Result: Student finds it hard to walk or slips

Common mistakes

• Thinking only the action force matters: Both action and reaction are always present and equal.
• Forgetting about friction: Without friction, action and reaction can't help you move forward.
• Believing you can walk on ice just like on the road: The low friction changes everything.
• Assuming reaction force disappears on ice: The force is still there, but it can't push you forward well because your foot slips.

Remember it

You move forward only if you can push backward — on ice, you slip because you can't grip and push!