An object of mass 5 kg falls from rest through a vertical distance of `20 m` and attains a velocity of 10 m/s. How much work is done by the resistance of the air on the object?
`(g=10m//s^(2))`.

Explanation

To find the work done by the resistance of the air on the object, we can follow these steps:

### Step 1: Identify the known values
- Mass of the object (m) = 5 kg
- Distance fallen (h) = 20 m
- Final velocity (v) = 10 m/s
- Acceleration due to gravity (g) = 10 m/s²

...