SI unit of velocity is
(i) m/s
(ii) `m//s^(2)`
(iii) m
(iv) s

Answer

To determine the SI unit of velocity, we can follow these steps:

### Step 1: Understand the Concept of Velocity
Velocity is defined as the rate of change of displacement with respect to time. It indicates how fast an object is moving and in which direction.

### Step 2: Identify the Components of Velocity
Velocity can be expressed mathematically as:
\[ \text{Velocity} (v) = \frac{\text{Displacement}}{\text{Time}} \]
Here, displacement is the shortest distance between the initial and final positions, and time is the duration over which this displacement occurs.

### Step 3: Determine the SI Units of Displacement and Time
- The SI unit of displacement is **meter (m)**.
- The SI unit of time is **second (s)**.

### Step 4: Combine the Units
Since velocity is displacement per unit time, we can combine the units:
\[ \text{SI unit of velocity} = \frac{\text{SI unit of displacement}}{\text{SI unit of time}} = \frac{m}{s} \]

### Step 5: Conclusion
Thus, the SI unit of velocity is **meter per second (m/s)**.

### Final Answer
The correct option is (i) m/s.

---