A speed of 45 km per hour is the same as

Options

A. `12.5` metre / second
B. 13 metre / second
C. 15 metre / second
D. 12 metre / second

Answer

To solve the problem of converting a speed of 45 km per hour to meters per second, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Conversion Factors**:
- We know that 1 kilometer (km) is equal to 1000 meters (m).
- We also know that 1 hour (h) is equal to 3600 seconds (s).

2. **Set Up the Conversion**:
- To convert kilometers per hour to meters per second, we can use the formula:
\[ \text{Speed in m/s} = \left(\text{Speed in km/h} \times \frac{1000 \text{ m}}{1 \text{ km}}\right) \div \left(\frac{3600 \text{ s}}{1 \text{ h}}\right) \]
- For our case, we substitute 45 km/h into the formula:
\[ \text{Speed in m/s} = \left(45 \times \frac{1000}{3600}\right) \]

3. **Perform the Calculation**:
- First, calculate the multiplication:
\[ 45 \times 1000 = 45000 \]
- Now divide by 3600:
\[ \frac{45000}{3600} \]

4. **Simplify the Division**:
- To simplify \( \frac{45000}{3600} \), we can divide both the numerator and the denominator by 900:
\[ \frac{45000 \div 900}{3600 \div 900} = \frac{50}{4} = 12.5 \]

5. **Final Result**:
- Therefore, the speed of 45 km/h is equal to 12.5 meters per second (m/s).

### Conclusion:
The speed of 45 km per hour is the same as **12.5 meters per second**.