Answer:
Given,
Mass, m = 2kg
Height or distance, s = 20m
Initial velocity, u = 0m/s
Acceleration due to gravity, g = 10m/s (It is 9.8m/s but can be assumed 10m/s for simplifying calculations)
(Because the object is is just dropped)
Final velocity, v = ?
Solution
v^2 = u^2 + 2as (u^2 means u raised to power 2)
=> v^2 = 0^2 + 2*10*20
=> v^2 = 400
=> v = 20
Thus the velocity just before the body strikes the ground will be 20m/s.