Which of the following is different from others ?

Options

A. Speed
B. Density
C. Force
D. Time

Explanation

To determine which of the following quantities is different from the others, we need to classify each option as either a scalar quantity or a vector quantity.

### Step-by-Step Solution:

1. **Identify the Options**:
- Option 1: Speed
- Option 2: Density
- Option 3: Force
- Option 4: Time

2. **Classify Each Quantity**:
- **Speed**: Speed is defined as the distance traveled per unit of time. It only has magnitude and no direction. Therefore, speed is a **scalar quantity**.
- **Density**: Density is defined as mass per unit volume. Both mass and volume are scalar quantities, so density is also a **scalar quantity**.
- **Force**: Force is defined by Newton's second law as mass times acceleration (F = ma). Force has both magnitude and direction (e.g., 10 N to the right). Therefore, force is a **vector quantity**.
- **Time**: Time is a measure of duration and does not have direction. Thus, time is a **scalar quantity**.

3. **Compare the Classifications**:
- Speed: Scalar
- Density: Scalar
- Force: Vector
- Time: Scalar

4. **Identify the Different Quantity**:
- From the classifications, we see that speed, density, and time are all scalar quantities, while force is the only vector quantity.

5. **Conclusion**:
- The quantity that is different from the others is **Force**.

### Final Answer:
**Force** is the quantity that is different from the others.

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