A ball is thrown vertically upward with a velocity 'u' from the balloon descending with velocity v. After what time, the ball will pass by the balloon ?

Explanation

To solve the problem of when a ball thrown vertically upward with an initial velocity \( u \) from a descending balloon with a velocity \( v \) will pass the balloon again, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Motion**:
- The balloon is descending with velocity \( v \).
- The ball is thrown upwards with an initial velocity \( u \).

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