# What is friction?

Why do balls roll? Why do apples fall from the trees? Why do some things slide across ice but not on carpet? What makes our bikes stop when we brake? We use all types of forces including friction, gravity and pushes and pulls when we exercise, ride bikes and drive cars. Engineers and Scientists use their knowledge of forces and motion to design things for our homes, work and school.

Last week we looked at friction by:

• Observing how friction is different with different surfaces
• Exploring what more or less friction feels like
• Using arrows to represent frictional forces

Friction is….

Friction is what happens when any two things rub against each other causing grip.

Our first experiment involved everyone wearing rubber gloves. We then had to rub our hands together and describe what it felt like. Some of our answers included

• rough
• bumpy
• slimy
• sticky
• hands becoming hot

Then everyone was given a small sample of detergent in their hands and we had to rub our hands again with the detergent and describe what it felt like. Some of our answers included:

• slippery
• easy to move your hands
• smooth

We discussed how the material that the glove is made of enables us to feel more grip when we rub our hands together. We also talked about how there was more friction when rubbing our hands together without the detergent than with the detergent because there was more grip. The more grip we have, the more friction there is between two objects.

We then worked in small teams to investigate the friction force between different surfaces. The surfaces included:

• table top
• carpet
• asphalt
• grass

We had to predict which surface would cause the most friction before testing each one. We used our trays as a heavy item that we had to push across each surface.

Most teams found that the grass surface caused the most friction when pushing the tray and the table top having the least amount of friction occurring.

To make something move, we need to apply enough force (transfer enough energy to the object) to overcome the force of friction trying to stop that movement.  This can be more difficult at times depending on the surface and object.

What did you learn about friction?

Which surface did you find caused the most friction and why?

Can you give an example from everyday life where friction plays a role?

## 7 thoughts on “What is friction?”

1. Cooper✈️✈️✈️

Dear mrs b
Friction is when to surface is being rub together

You had because it has bumps ,ruf surface

By Cooper ✈️✈️✈️✈️

2. piper

Dear Mrs Baldwin,
What i learnt about friction was that friction doesn’t happen when your just standing still it only happens if you run.My group found that the gravel had the most friction against the tray because the gravel was bumpy and ruff.

3. Mackenzie

Dear Mrs baldwin,

The thing that I learnt about friction was that the warmness was just an side affect and how friction works.
The grass had the most friction because it is really bumpy and the asphalt was the same.
When you are walking to school or walking some where.

From Mackenzie.

4. Mateja.com.au

Deer mrs baldwin, I got ashfelt as the one that had the most friction because its the sharpest and the hardest to push on.
You use friction when you walk and play sport and you do that all day.

5. Jessicam

dear miss baldwin friction is when to surface is being rub together .and in every day life friction is when we walk because our shoes rub to the floor so thats friction .from Jess m

6. Elyssa

Dear Miss Baldwin
That when 2 things rub together it makes a grip.
friction happens when you walk because your foot is rubbing with the floor.

From Elyssa

7. Jackson

Dear Mrs Baldwin,
The surface that had the most friction and why is the grass and it had the most friction because it had dirt underneath so it had a rough surface.
where friction plays a role in evryday life if is when you’re running.

From Jackson