The velocity of a body at rest is always

Options

A. unity
B. negative
C. zero
D. infinite

Answer

To solve the question regarding the velocity of a body at rest, we can follow these steps:

### Step 1: Understand the Definition of Velocity
Velocity is defined as the rate of change of displacement with respect to time. Mathematically, it is expressed as:
\[ v = \frac{ds}{dt} \]
where \( v \) is the velocity, \( s \) is the displacement, and \( t \) is the time.

### Step 2: Analyze the Condition of a Body at Rest
A body is considered to be at rest when it does not change its position over time. This means that its displacement remains constant.

### Step 3: Determine the Displacement of a Body at Rest
If a body is at rest, its displacement does not change. Therefore, if we denote the displacement as \( s \), it remains constant over time:
\[ s = \text{constant} \]

### Step 4: Calculate the Velocity
Since the displacement is constant, the change in displacement (\( ds \)) over any time interval (\( dt \)) is zero:
\[ ds = 0 \]
Thus, substituting into the velocity equation:
\[ v = \frac{ds}{dt} = \frac{0}{dt} = 0 \]

### Step 5: Conclusion
The velocity of a body at rest is always zero.

### Final Answer
The velocity of a body at rest is always **zero**.

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