Convert each of the following speeds in to km /hr :
3.5 m/sec

Answer

To convert the speed from meters per second (m/sec) to kilometers per hour (km/hr), follow these steps:

### Step-by-Step Solution:

1. **Understand the Conversion Factors**:
- 1 kilometer = 1000 meters
- 1 hour = 3600 seconds

2. **Convert the Speed**:
- We have a speed of 3.5 m/sec.
- To convert meters to kilometers, we use the conversion factor:
\[ 1 \text{ meter} = \frac{1}{1000} \text{ kilometers} \]
- To convert seconds to hours, we use the conversion factor:
\[ 1 \text{ second} = \frac{1}{3600} \text{ hours} \]

3. **Set Up the Conversion**:
- We can express 3.5 m/sec in terms of km/hr:
\[ 3.5 \text{ m/sec} = 3.5 \times \left(\frac{1 \text{ km}}{1000 \text{ m}}\right) \times \left(\frac{3600 \text{ sec}}{1 \text{ hr}}\right) \]

4. **Calculate the Conversion**:
- Now, perform the multiplication:
\[ 3.5 \times \frac{3600}{1000} \]
- Simplifying this:
\[ = 3.5 \times 3.6 \]
- Calculate the result:
\[ = 12.6 \text{ km/hr} \]

5. **Final Answer**:
- The speed of 3.5 m/sec is equal to **12.6 km/hr**.