A particle is moving in a circle with uniform speed. IT has constant

Options

A. velocity
B. Acceleration
C. kinetic energy
D. displacement

Answer

To solve the question, we need to analyze the motion of a particle moving in a circle with uniform speed and determine which of the given options is constant.

### Step-by-Step Solution:

1. **Understanding the Motion**:
- A particle is moving in a circular path with uniform speed. This means that while the speed (magnitude of velocity) remains constant, the direction of the particle's velocity is continuously changing.

2. **Analyzing Velocity**:
- Velocity is a vector quantity, which means it has both magnitude and direction. Since the direction of the particle's motion changes at every point along the circular path, the velocity is not constant.
- **Conclusion**: Velocity is not constant.

3. **Analyzing Acceleration**:
- Acceleration is defined as the rate of change of velocity. Since the velocity is changing (due to the change in direction), the acceleration is also changing.
- In circular motion, there is centripetal acceleration directed towards the center of the circle, and if there is any tangential acceleration (due to changes in speed), it would also contribute to the overall acceleration.
- **Conclusion**: Acceleration is not constant.

4. **Analyzing Kinetic Energy**:
- Kinetic energy (KE) is given by the formula \( KE = \frac{1}{2}mv^2 \), where \( m \) is mass and \( v \) is speed.
- Since the speed of the particle is constant and the mass is also constant, the kinetic energy remains constant throughout the motion.
- **Conclusion**: Kinetic energy is constant.

5. **Analyzing Displacement**:
- Displacement is the shortest distance from the initial to the final position of the particle. As the particle moves around the circle, its displacement changes continuously.
- For example, when the particle returns to its starting point, the displacement is zero, but at other points, it has a non-zero value.
- **Conclusion**: Displacement is not constant.

### Final Answer:
The only quantity that remains constant as the particle moves in a circle with uniform speed is **kinetic energy**.