Name the quantity whose unit is 'Newton' (N).

Options

A. Force
B. Pressure
C. Viscosity
D. Density

Answer

**Step-by-Step Solution:**

1. **Identify the Unit**: The question asks for the quantity that is measured in Newtons (N).

2. **Recall the Definition of Force**: In physics, force is defined as an interaction that causes an object to change its velocity (which includes starting, stopping, or changing direction).

3. **Understand the Formula for Force**: The formula for force is given by Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a):
\[ F = m \times a \]

4. **Units of Mass and Acceleration**: The SI unit of mass is kilograms (kg) and the SI unit of acceleration is meters per second squared (m/s²).

5. **Combine Units**: Therefore, when we express force in terms of its base units, we have:
\[ \text{Force} = \text{mass} \times \text{acceleration} = \text{kg} \times \text{m/s}^2 \]

6. **Recognize the Unit of Force**: The combined unit kg·m/s² is defined as one Newton (N). Thus, we conclude that the quantity measured in Newtons is force.

7. **Final Answer**: The quantity whose unit is 'Newton' (N) is **Force**.

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