Question

a stone of mass 2kg is dropped from aheight of 4m. Neglecting air resistance the kinetic energy of stone in joules just before it hits the ground is (g= 10m/s)​

Answer 1

Explanation:

Given :  h=40 m             m=2kg                     u=0m/s

Force due to air resistance      f=20N

Acceleration of the stone     a=g−mf=10−220=0  m/s2

Using      v2−u2=2aS

∴   v2−0=2(0)×40                     ⟹v=0m/s