Express 15 `m s^(-1) ` in km `h^(-1)` .

Explanation

To convert 15 m/s to km/h, we can follow these steps:

### Step 1: Understand the conversion factors
1 kilometer (km) is equal to 1000 meters (m), and 1 hour (h) is equal to 3600 seconds (s). Therefore, we can express the conversion from km/h to m/s as follows:
\[ 1 \text{ km/h} = \frac{1000 \text{ m}}{3600 \text{ s}} = \frac{1000}{3600} \text{ m/s} \]

### Step 2: Simplify the conversion factor
We can simplify \(\frac{1000}{3600}\):
\[ \frac{1000}{3600} = \frac{5}{18} \text{ m/s} \]
This means that 1 m/s is equivalent to \(\frac{18}{5}\) km/h.

### Step 3: Set up the conversion for 15 m/s
Now we need to convert 15 m/s to km/h using the conversion factor derived:
\[ 15 \text{ m/s} = 15 \times \frac{18}{5} \text{ km/h} \]

### Step 4: Calculate the result
Now, perform the multiplication:
\[ 15 \times \frac{18}{5} = \frac{15 \times 18}{5} = \frac{270}{5} = 54 \text{ km/h} \]

### Final Answer
Thus, 15 m/s is equal to 54 km/h.

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