At what angle must a railway track with a level of 300 m radius be banked for safe running of trains at a speed of `90 km h^(-1)` ?

Explanation

To find the angle at which a railway track must be banked for safe running of trains at a speed of 90 km/h on a curve with a radius of 300 m, we can follow these steps:

### Step-by-Step Solution:

1. **Convert Speed from km/h to m/s:**
\[ \text{Speed (v)} = 90 \, \text{km/h} = 90 \times \frac{1000 \, \text{m}}{3600 \, \text{s}} = 25 \, \text{m/s} \]
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