Which of the following statement is incorrect ?

Options

A. static friction is greater than rolling friction
B. sliding friction is less than rolling friction
C. rolling friction is less than static friction
D. static friction is greater than sliding friction

Answer

To determine which of the statements is incorrect regarding friction, let's analyze each option step by step.

### Step 1: Understand the Types of Friction
- **Static Friction**: This is the friction that exists between a stationary object and the surface on which it rests. It prevents the object from starting to move.
- **Sliding Friction**: This is the friction that occurs when two surfaces slide against each other.
- **Rolling Friction**: This is the friction that occurs when an object rolls over a surface.

### Step 2: Analyze Each Statement
1. **Option 1**: Static friction is greater than rolling friction.
- This statement is generally true. Static friction is typically greater than rolling friction because it requires more force to start moving an object from rest than to keep it rolling.

2. **Option 2**: Sliding friction is less than rolling friction.
- This statement is incorrect. Sliding friction is usually greater than rolling friction. When an object rolls, it has less contact area with the surface compared to when it slides, resulting in less friction.

3. **Option 3**: Rolling friction is less than static friction.
- This statement is true. Rolling friction is less than static friction, as it is easier to keep an object rolling than to start moving it from rest.

4. **Option 4**: Static friction is greater than sliding friction.
- This statement is true. Static friction is generally greater than sliding friction because it takes more force to overcome static friction than to keep an object sliding.

### Step 3: Identify the Incorrect Statement
From the analysis:
- **Option 2** is the incorrect statement because sliding friction is not less than rolling friction; it is usually greater.

### Final Answer
The incorrect statement is **Option 2: Sliding friction is less than rolling friction**.

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