A persons croses a 600 m long street in 5 minutes. What is his speed in km per hour?

Answer

To find the speed of a person who crosses a 600 m long street in 5 minutes, we can follow these steps:

### Step 1: Convert time from minutes to seconds
Since speed is usually calculated in meters per second or kilometers per hour, we need to convert the time from minutes to seconds.

- **Calculation**:
\[ \text{Time in seconds} = 5 \text{ minutes} \times 60 \text{ seconds/minute} = 300 \text{ seconds} \]

### Step 2: Use the formula for speed
The formula for speed is given by:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Here, the distance is 600 meters and the time is 300 seconds.

- **Calculation**:
\[ \text{Speed} = \frac{600 \text{ m}}{300 \text{ s}} = 2 \text{ m/s} \]

### Step 3: Convert speed from meters per second to kilometers per hour
To convert the speed from meters per second to kilometers per hour, we use the conversion factor \( \frac{18}{5} \).

- **Calculation**:
\[ \text{Speed in km/h} = 2 \text{ m/s} \times \frac{18}{5} = \frac{36}{5} \text{ km/h} \]

### Step 4: Final result
Now, we can express the speed in a more understandable form:
\[ \text{Speed} = 7.2 \text{ km/h} \]

### Summary of the Steps:
1. Convert time from minutes to seconds: \( 5 \text{ min} = 300 \text{ s} \)
2. Calculate speed in m/s: \( \text{Speed} = \frac{600 \text{ m}}{300 \text{ s}} = 2 \text{ m/s} \)
3. Convert speed to km/h: \( \text{Speed} = 2 \text{ m/s} \times \frac{18}{5} = \frac{36}{5} \text{ km/h} \)
4. Final speed: \( 7.2 \text{ km/h} \)