Which of the following is not a vector?

Options

A. Angular momentum
B. Angular impulse
C. Kinetic energy
D. Magnetic Intensity

Explanation

To determine which of the following options is not a vector, we need to analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Options**: We have four options to consider:
- Option 1: Angular Momentum
- Option 2: Angular Impulse
- Option 3: Kinetic Energy
- Option 4: Magnetic Intensity

2. **Analyze Option 1: Angular Momentum**:
- Angular momentum (L) is defined as the cross product of the position vector (R) and linear momentum vector (P):
\[ L = R \times P \]
- Since it is derived from the cross product of two vectors, angular momentum is a vector quantity.

**Hint**: Remember that the cross product of two vectors results in another vector.

3. **Analyze Option 2: Angular Impulse**:
- Angular impulse is defined as torque (τ) multiplied by a time interval (dt):
\[ \text{Angular Impulse} = \tau \cdot dt \]
- Torque (τ) is also a vector quantity, and since time (dt) is a scalar, the product of a vector and a scalar remains a vector. Thus, angular impulse is a vector.

**Hint**: The product of a vector and a scalar is still a vector.

4. **Analyze Option 3: Kinetic Energy**:
- Kinetic energy (KE) is defined as:
\[ KE = \frac{1}{2} mv^2 \]
- Here, m is mass (a scalar) and v is velocity (a vector). However, when calculating kinetic energy, we square the velocity, which makes it a scalar quantity. Therefore, kinetic energy is not a vector.

**Hint**: Energy is a scalar quantity, regardless of the vector nature of velocity in its formula.

5. **Analyze Option 4: Magnetic Intensity**:
- Magnetic intensity is related to the magnetic moment (a vector) divided by volume (a scalar):
\[ \text{Magnetic Intensity} = \frac{M}{V} \]
- Since the magnetic moment is a vector and volume is a scalar, the resultant magnetic intensity remains a vector.

**Hint**: Division of a vector by a scalar retains the vector nature.

6. **Conclusion**:
- After analyzing all options, we find that:
- Angular Momentum (Option 1) is a vector.
- Angular Impulse (Option 2) is a vector.
- Kinetic Energy (Option 3) is **not a vector**.
- Magnetic Intensity (Option 4) is a vector.
- Therefore, the correct answer is **Option 3: Kinetic Energy**.

### Final Answer:
**Kinetic Energy is not a vector.**