A Bullet Train in Japan starting from rest accelerates uniformly at `0.5m s^(-2)` for 2 minutes. It then maintains uniform speed for 20 minutes and then retards uniformly at the rate of `0.25 m s^(-1)` and comes to rest. Calculate the average speed of the train

Explanation

To solve the problem of calculating the average speed of the Bullet Train, we will break it down into three main phases: acceleration, uniform speed, and deceleration.

### Step 1: Calculate the distance covered during acceleration (S1)

1. **Given Data:**
- Initial velocity (U) = 0 m/s (starting from rest)
- Acceleration (A) = 0.5 m/s²
- Time (T1) = 2 minutes = 2 × 60 = 120 seconds
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