Two train are moving in a straight line in the same direction with a speed of 80 km/h. The relative velocity of one trains w.r.t. each other is

Options

A. 80 km/h
B. 40 km/h
C. Zero
D. 160 km/h

Answer

To find the relative velocity of one train with respect to the other when both trains are moving in the same direction at the same speed, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Speeds of the Trains**:
- Let the speed of Train A = 80 km/h.
- Let the speed of Train B = 80 km/h.

2. **Understand Relative Velocity**:
- The relative velocity of one object with respect to another is calculated using the formula:
\[ \text{Relative Velocity of A w.r.t. B} = \text{Velocity of A} - \text{Velocity of B} \]

3. **Substitute the Values**:
- Using the speeds identified:
\[ \text{Relative Velocity of A w.r.t. B} = 80 \text{ km/h} - 80 \text{ km/h} \]

4. **Calculate the Result**:
- Performing the subtraction:
\[ \text{Relative Velocity of A w.r.t. B} = 0 \text{ km/h} \]

5. **Conclusion**:
- The relative velocity of one train with respect to the other is 0 km/h, meaning they are moving at the same speed in the same direction.

### Final Answer:
The relative velocity of one train with respect to the other is **0 km/h**.

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