A ball bounce of `80%` of its original height . What fraction of its mechanical energy is lost in each bounce ?

Explanation

To solve the problem of how much mechanical energy is lost in each bounce of a ball that bounces back to 80% of its original height, we can follow these steps:

### Step 1: Determine Initial Mechanical Energy
When the ball is dropped from height \( h \), its initial mechanical energy (E_initial) is purely potential energy since it starts from rest. The formula for potential energy (PE) is:
\[ E_{\text{initial}} = mgh \]
where:
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