A train is running at 45 km per hour . How far does it go in 8 seconds?

Answer

To solve the problem of how far a train running at 45 km per hour travels in 8 seconds, we can follow these steps:

### Step 1: Convert speed from kilometers per hour to meters per second.
We know that:
- 1 kilometer = 1000 meters
- 1 hour = 3600 seconds

To convert the speed:
\[ \text{Speed in m/s} = \text{Speed in km/h} \times \frac{1000 \text{ m}}{3600 \text{ s}} \]
Substituting the given speed:
\[ \text{Speed in m/s} = 45 \times \frac{1000}{3600} \]

### Step 2: Simplify the conversion.
Calculating the conversion:
\[ \text{Speed in m/s} = 45 \times \frac{1000}{3600} = \frac{45000}{3600} \]
Now, we can simplify this fraction:
\[ \frac{45000}{3600} = \frac{4500}{360} = \frac{450}{36} = \frac{150}{12} = \frac{25}{2} = 12.5 \text{ m/s} \]

### Step 3: Calculate the distance traveled in 8 seconds.
We use the formula:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
Substituting the values we have:
\[ \text{Distance} = 12.5 \text{ m/s} \times 8 \text{ s} \]

### Step 4: Perform the multiplication.
Calculating the distance:
\[ \text{Distance} = 12.5 \times 8 = 100 \text{ meters} \]

### Final Answer:
The train travels **100 meters** in 8 seconds.

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