A particle moves with uniform velocity. Which of the following statements about the motion of the particle is true?

Options

A. Its speed is zero.
B. Its acceleration is zero.
C. Its acceleration is opposite to the velocity.
D. Its speed may be variable.

Explanation

To determine which statement about the motion of a particle moving with uniform velocity is true, we can analyze the definitions and characteristics of uniform velocity.

### Step-by-Step Solution:

1. **Definition of Uniform Velocity**:
- A particle is said to be moving with uniform velocity if it covers equal displacements in equal intervals of time.
- This implies that both the speed and direction of the particle remain constant.

2. **Understanding Acceleration**:
- Acceleration is defined as the change in velocity over time. Mathematically, it is expressed as:
\[ a = \frac{\Delta v}{\Delta t} \]
- Since the velocity is constant (uniform), there is no change in velocity, which means:
\[ \Delta v = 0 \Rightarrow a = 0 \]
- Therefore, the acceleration of the particle is zero.

3. **Evaluating the Statements**:
- **Statement 1**: "Its speed is zero."
- This is incorrect because uniform velocity means the particle has a constant speed, which is not necessarily zero.
- **Statement 2**: "Acceleration is zero."
- This is correct, as derived above.
- **Statement 3**: "Acceleration is opposite to the velocity."
- This is incorrect because the acceleration is zero, and thus there is no direction to oppose.
- **Statement 4**: "Speed may be variable."
- This is incorrect since uniform velocity implies constant speed.

4. **Conclusion**:
- The only true statement about the motion of the particle moving with uniform velocity is that **acceleration is zero**.

### Final Answer:
The correct statement is: **Acceleration is zero.**