Newton - second is the unit of

Options

A. energy
B. momentum
C. angular momentum
D. velocity

Explanation

To determine what the unit "Newton-second" represents, we can analyze the relationship between force, momentum, and impulse. Here’s a step-by-step solution:

### Step 1: Understand the definition of Newton
- A Newton (N) is the unit of force in the International System of Units (SI). It is defined as the force required to accelerate a mass of one kilogram at a rate of one meter per second squared (1 N = 1 kg·m/s²).

### Step 2: Relate Newton to momentum
- Momentum (p) is defined as the product of mass (m) and velocity (v):
\[ p = m \cdot v \]
- The unit of momentum is therefore kg·m/s.

### Step 3: Understand impulse
- Impulse (J) is defined as the change in momentum, which can also be expressed as the product of force (F) and the time duration (t) over which the force acts:
\[ J = F \cdot t \]
- The unit of impulse is also kg·m/s, which is the same as the unit of momentum.

### Step 4: Analyze the unit Newton-second
- If we express impulse in terms of its components:
\[ J = F \cdot t = (N) \cdot (s) \]
Since 1 N = 1 kg·m/s², we can write:
\[ J = (kg \cdot m/s²) \cdot s = kg \cdot m/s \]
- This shows that Newton-seconds (N·s) is indeed the unit of momentum.

### Conclusion
- Therefore, the unit "Newton-second" is the unit of momentum.

### Final Answer
- **Newton-second is the unit of momentum.**