A body of mass 'm is drhopped from a height 'h'. The speed with which body hits the ground is `sqrt(0.9gh)` Find the work done by air-resistance furing its fall.

Explanation

To solve the problem of finding the work done by air resistance during the fall of a body dropped from a height \( h \), we can follow these steps:

### Step 1: Understand the Problem
We have a body of mass \( m \) dropped from a height \( h \). The final speed of the body just before it hits the ground is given as \( v = \sqrt{0.9gh} \). We need to find the work done by air resistance during its fall.

### Step 2: Apply the Work-Energy Theorem
According to the work-energy theorem, the total work done on an object is equal to its change in kinetic energy. The formula for kinetic energy (KE) is:
\[
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