Sliding friction of flattened tyre is more than unflattened tyre. This is due to

Options

A. more surfaces Area in contact
B. Increae of Normal reaction
C. Increase of interlocking (change in nature of surface)
D. Change in nature of material in contact

Answer

To understand why the sliding friction of a flattened tire is more than that of an unflattened tire, we can break down the explanation into a step-by-step solution:

### Step 1: Define the Two Cases
- **Case 1: Flattened Tire** - A tire that has no air inside it, causing it to be flat against the ground.
- **Case 2: Unflattened Tire** - A tire that is properly inflated, maintaining its round shape.

### Step 2: Analyze the Area of Contact
- In the case of the **flattened tire**, the entire bottom surface of the tire is flat against the ground. This results in a larger area of contact between the tire and the surface.
- In the case of the **unflattened tire**, the bottom of the tire is curved, which means that only a small part of the tire is in contact with the ground. This results in a smaller area of contact.

### Step 3: Understand Friction
- Friction is the force that opposes the motion of two surfaces sliding against each other. The amount of friction depends on the area of contact and the nature of the surfaces in contact.
- Generally, a larger area of contact leads to increased friction because more surface area is available for the frictional forces to act.

### Step 4: Compare the Friction in Both Cases
- In the **flattened tire**, since there is a larger area of contact, the frictional force is greater. This means that the sliding friction is higher.
- In the **unflattened tire**, with a smaller area of contact, the frictional force is lower, resulting in less sliding friction.

### Conclusion
- Therefore, the sliding friction of a flattened tire is more than that of an unflattened tire due to the larger area of contact with the ground in the flattened state, which increases the frictional force.

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