## Welcome to our DIY Activity Ideas blog post for high school teachers and homeschooling parents! In this post, we will explore four exciting activities to teach and demonstrate the concept of friction. Friction is a fundamental force that affects our daily lives in numerous ways. From how vehicles come to a stop using disc brakes to how printers smoothly feed paper using rollers, understanding friction is essential in engineering and everyday applications.

What is friction?
Every object has surfaces. Surface of an object is the outer or the topmost boundary of an object.

Every surface at a microscopic level have irregularities.

When two surfaces come in contact, irregularities in the surfaces get locked

The locking of irregularities in surfaces creates an opposing force to motion between them. This opposing force is called friction. Friction is a force that opposes motion between 2 objects.

Static friction
Where stationary
[Enough time for locking contact points]

Sliding friction
[Less Hane for locking logging contact points]

Rolling friction
[No time for contact points]

When you are pushing a car at rest, the force required to move it is more. When the car starts to move, the force required to move it is less.

Disc brakes in automobiles.
The disc brake is a lot like the brakes on a bicycle. Bicycle brakes have a caliper, which squeezes the brake pads against the wheel. In a disc brake, the brake pads squeeze the disc instead of the wheel, and the force is transmitted hydraulically instead of through a cable. Friction between the pads and the disc slows the disc down.

## Materials Required:

•  Syringes
• foam sheet
• mortar
• rubber bands
• cardboard
• a small model wheel

## Materials image (remove this text )

##### Procedure:
• Cut two circular shapes from the foam sheet, representing the brake pads.
• Attach the foam brake pads to the syringes using rubber bands.
• Create a small model wheel using cardboard and attach it to the mortar.
• Rotate the wheel and simultaneously squeeze the syringes to simulate the brake pads pressing against the wheel.
• Observe how the friction between the brake pads and the wheel slows down the rotation.

## Materials Required:

•  Syringes
• foam sheet
• mortar
• cardboard
• rubber bands
• tracing paper and OHP paper

## Materials image (remove this text )

##### Procedure:
• Use the model from activity 1
• Push the wheel near the flat surface
• Now take the paper  and insert it between the wheel and surface and observe the moment of paper
• Repeat the same with OHP paper and tracing paper

## Materials Required:

•  Disc
• ring
• various lubricants (e.g., oil, grease, water).

## Materials image (remove this text )

##### Procedure:
• Insert the disc into the ring and try to rotate the ring
• Now use a lubricant and apply on the sides of the disc and try to rotate  the ring.
• Repeat the process using different lubricants applied to the disc’s surface.
• Observe and record how the lubricants affect the friction and the rotation of ring.

What’s happening?
Lubricant applied will fill-in the gaps (irregularities) in the surface. This reduces the friction between the discs while rotating.

## Materials Required:

• Ring
• disc
• plastic sheet
• cardboard.
##### Procedure:
• Attach the ring to the disc using the plastic sheet.
• Place small beads between the ring and the disc, acting as ball bearings.
• Slide the model across a flat surface and compare the resistance experienced with and without the ball bearings.
• Discuss with the students how the ball bearings reduce friction and make the movement smoother.

## Evolution of Science “Friction”

How to Start a Fire without Matches?
Fire through Friction,rubbing two sticks together is likely the oldest of all fire-starting techniques

## Tribology - Key to Lower Friction and Higher Efficiency

Charles August Coulomb (1736-1806) – Designed the first tribometer.
The tribometer is a device which measures the coefficient of friction of a certain material. Today, wear is the number one cause for the end of useful Product Life.

Tribology helps in choosing and developing new materials that can reduce friction and wear. A few of the applications are shown – Wind Turbines, Automotives,  Aircrafts

## Current area of research

The invention of the atomic force microscope (AFM) in 1986 enabled scientists to study friction at atomic scale. With the basic ‘mechanisms of friction at atomic scale understood, it must be studied how these ‘mechanisms change with the contact area at macroscopic scale.

# Counting in Groups

These activities provide a practical and engaging way to teach students about friction. Through hands-on exploration, students will gain a deeper understanding of how different types of friction work and their applications in everyday life. Have fun conducting these activities and fostering a love for science and experimentation in your students!