Choose the correct statement(s).

Options

A. Both speed and velocity have the same units.
B. If a body has a speed of 50 m `s^(-1)` in a straight line path, then its velocity is 180 km `h^(-1)`.
C. The speed of a vehicle is measured by a device called speedometer.
D. All of the above

Explanation

To solve the question "Choose the correct statement(s)", we will analyze each option provided in the question step by step.

### Step 1: Analyze Option 1
**Statement:** Both speed and velocity have the same units.

- **Explanation:** Speed is defined as the distance traveled per unit of time, and its unit is meters per second (m/s). Velocity, which is a vector quantity, also has the same unit of meters per second (m/s). Therefore, this statement is **correct**.

### Step 2: Analyze Option 2
**Statement:** If a body has a speed of 50 meters per second in a straight line path then its velocity is 180 km per hour.

- **Explanation:** In a straight line, speed and velocity are equal in magnitude. The speed given is 50 m/s. To convert this to kilometers per hour (km/h), we use the conversion factor:
- 1 m/s = 3.6 km/h.

Therefore,
\[ 50 \, \text{m/s} \times 3.6 \, \text{km/h per m/s} = 180 \, \text{km/h}. \]
This means that the velocity is indeed 180 km/h when converted correctly. Hence, this statement is **correct**.

### Step 3: Analyze Option 3
**Statement:** The speed of a vehicle is measured by a device called speedometer.

- **Explanation:** A speedometer is a device used in vehicles to measure the speed at which the vehicle is traveling. This statement is also **correct**.

### Step 4: Analyze Option 4
**Statement:** All of the above.

- **Explanation:** Since all the previous statements (1, 2, and 3) have been determined to be correct, this statement is also **correct**.

### Conclusion
Based on the analysis of all options, the correct answer is:
**All of the above (Option 4)**.