`1kmh^(-1)` = _______ `ms^(-1)`.

Options

A. `50/3`
B. `5/18`
C. `18/5`
D. `5/8`

Explanation

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

### Step-by-Step Solution:

1. **Understand the Units**:
- We need to convert kilometers to meters and hours to seconds.
- 1 kilometer (km) = 1000 meters (m).
- 1 hour = 60 minutes, and 1 minute = 60 seconds, so 1 hour = 60 × 60 = 3600 seconds.

2. **Set Up the Conversion**:
- We start with the conversion factor for 1 km/h:
\[ 1 \text{ km/h} = \frac{1 \text{ km}}{1 \text{ hour}} \]

3. **Convert Kilometers to Meters**:
- Replace kilometers with meters:
\[ 1 \text{ km/h} = \frac{1000 \text{ m}}{1 \text{ hour}} \]

4. **Convert Hours to Seconds**:
- Replace hours with seconds:
\[ 1 \text{ hour} = 3600 \text{ seconds} \]
- Thus, we can rewrite the equation:
\[ 1 \text{ km/h} = \frac{1000 \text{ m}}{3600 \text{ s}} \]

5. **Simplify the Fraction**:
- Now, simplify \(\frac{1000}{3600}\):
\[ \frac{1000}{3600} = \frac{1000 \div 200}{3600 \div 200} = \frac{5}{18} \]
- Therefore:
\[ 1 \text{ km/h} = \frac{5}{18} \text{ m/s} \]

### Final Answer:
\[ 1 \text{ km/h} = \frac{5}{18} \text{ m/s} \]

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