A uniform iron bar of length7 m weight 22.4 kg. How much does the same bar of length 13 m weight ?

Answer

To find the weight of a uniform iron bar of length 13 m, given that a 7 m bar weighs 22.4 kg, we can use the concept of ratios.

### Step-by-Step Solution

1. **Determine the weight of 1 meter of the bar:**
- The weight of the 7 m bar is 22.4 kg.
- To find the weight of 1 meter of the bar, we divide the total weight by the length of the bar:
\[ \text{Weight of 1 m bar} = \frac{22.4 \text{ kg}}{7 \text{ m}} = 3.2 \text{ kg/m} \]

2. **Calculate the weight of the 13 m bar:**
- Now that we know the weight of 1 meter of the bar, we can find the weight of the 13 m bar by multiplying the weight of 1 meter by the length of the new bar:
\[ \text{Weight of 13 m bar} = 3.2 \text{ kg/m} \times 13 \text{ m} = 41.6 \text{ kg} \]

### Final Answer
The weight of the 13 m bar is **41.6 kg**.