A rain drop of radius 2mm, falls from a height of 500 m above the ground. It falls with decreasing acceleration due to viscous resistance of air until half its original height. It attains its maximum (terminal ) speed, and moves with uniform speed there after. What is the work done by the gravitational force on the drop in the first half and second half of its journey ? Take density of water `=10^(3)kg//m^(3)`. What is the work done by the resistive force in the entire journey if its speed on reaching the ground is `10ms^(-1)` ?

Explanation

To solve the problem step by step, we will calculate the work done by the gravitational force during the first and second halves of the journey of the raindrop, and then we will find the work done by the resistive force during the entire journey.

### Step 1: Calculate the Work Done by Gravitational Force in the First Half of the Journey (A to B)

1. **Identify the height change**: The raindrop falls from a height of 500 m to 250 m. The change in height (h) is:
\[ h = 500 \, \text{m} - 250 \, \text{m} = 250 \, \text{m} \]
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