A body falling from a height of 10m rebounds from hard floor. If it loses 20% energy in the impact, then coefficient of restitution is
0.89
0.56
0.23
0.18
As 20% energy lost in collision therefore
mgh2=80% of mgh1 ⇒h2h1=0.8
but e=h2h1=0.8=0.89