A train is 125m long. If the train takes 30 seconds to cross a tree by the railway line, then the speed of the train is

Options

A. 14km/hr
B. 15km/hr
C. 16km/hr
D. 12km/hr

Answer

To find the speed of the train, we can follow these steps:

### Step 1: Identify the Length of the Train
The length of the train is given as 125 meters.

### Step 2: Identify the Time Taken to Cross the Tree
The time taken by the train to cross the tree is given as 30 seconds.

### Step 3: Use the Formula for Speed
The formula for speed is given by:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
In this case, the distance is the length of the train (125 m) and the time is 30 seconds.

### Step 4: Substitute the Values into the Formula
Substituting the values into the formula, we have:
\[ \text{Speed} = \frac{125 \text{ m}}{30 \text{ s}} \]

### Step 5: Calculate the Speed
Now, we perform the division:
\[ \text{Speed} = \frac{125}{30} \approx 4.17 \text{ m/s} \]

### Step 6: Convert Speed to km/h (if required)
To convert the speed from meters per second to kilometers per hour, we can use the conversion factor (1 m/s = 3.6 km/h):
\[ \text{Speed in km/h} = 4.17 \text{ m/s} \times 3.6 \approx 15 \text{ km/h} \]

### Final Answer
The speed of the train is approximately **4.17 m/s** or **15 km/h**.

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