In an oscillating pendulum, KE is ............ at extremes.

Options

A. zero
B. negative
C. positive
D. none of these

Explanation

To solve the question "In an oscillating pendulum, KE is ............ at extremes," we need to analyze the behavior of the pendulum at its extreme positions.

### Step-by-Step Solution:

1. **Understanding the Pendulum's Motion**:
- A pendulum oscillates back and forth around a central position (equilibrium). It has maximum displacement at two points, known as the extremes (one on either side of the central position).

2. **Velocity at Extreme Positions**:
- At the extreme positions of the pendulum's swing, the pendulum momentarily comes to a stop before changing direction. This means that the velocity of the pendulum at these points is zero.

3. **Kinetic Energy Formula**:
- Kinetic Energy (KE) is given by the formula:
\[ KE = \frac{1}{2} m v^2 \]
where \( m \) is the mass of the pendulum and \( v \) is its velocity.

4. **Substituting Velocity**:
- Since we established that the velocity \( v \) is zero at the extremes, we can substitute this value into the kinetic energy formula:
\[ KE = \frac{1}{2} m (0)^2 = 0 \]

5. **Conclusion**:
- Therefore, at the extreme positions of an oscillating pendulum, the kinetic energy is zero.

### Final Answer:
The correct answer is: **0**.

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