A ballon starting from the ground has been ascending vertically at a uniform veloctiy for 4.5 sec and a stone let fall from it reaches the ground in 7 sec. Find the velocity of the ballon and its heigth when the stone was let fall.

Explanation

To solve the problem step by step, let's break it down into manageable parts.

### Given:
1. Time of ascent of the balloon, \( t_b = 4.5 \) seconds.
2. Total time taken by the stone to reach the ground after being released from the balloon, \( t_s = 7 \) seconds.
3. Acceleration due to gravity, \( g = 9.8 \, \text{m/s}^2 \).

### Step 1: Determine the height of the balloon when the stone is released.
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