Express the speed of 18 m/s in km/h.

Options

A. 5
B. 32.4
C. 64.8
D. 129.16

Answer

To convert the speed from meters per second (m/s) to kilometers per hour (km/h), we can follow these steps:

1. **Understand the conversion factor**:
- We know that 1 meter is equal to 0.001 kilometers and 1 second is equal to 1/3600 hours. Therefore, to convert m/s to km/h, we multiply by 3.6 (since 1000 meters = 1 kilometer and 3600 seconds = 1 hour).

2. **Set up the equation**:
- We have the speed given as 18 m/s. To convert this to km/h, we will use the conversion factor:
\[ \text{Speed in km/h} = \text{Speed in m/s} \times 3.6 \]

3. **Perform the calculation**:
- Substitute the value of speed in m/s into the equation:
\[ \text{Speed in km/h} = 18 \, \text{m/s} \times 3.6 \]

4. **Calculate the product**:
- Now, we will multiply:
\[ 18 \times 3.6 = 64.8 \]

5. **Final answer**:
- Therefore, the speed of 18 m/s is equal to 64.8 km/h.

### Summary of Steps:
1. Understand the conversion factor (1 m/s = 3.6 km/h).
2. Set up the equation for conversion.
3. Substitute the given speed into the equation.
4. Multiply to find the result.
5. State the final answer.