Question

A body of mass 3kg starts falling down from rest position after 3 second what will be its kinetic energy if g = 10m/s^2 ?

Answer 1

we use 1 equation of motion
v=u+at
v=0+10×3
v=30 m/s
kinetic energy =1/2mv^2
=1/2×3×30×30
=3×15×30
=45×30
=1350

Answer 2

v=u+at v=0+10*3=30m/s
k.e=1/2*3*30*30=45*30=1350joules