Solution:
H1 =10 m, v1 =?
Loss of energy =40% H2 =?
On striking the floor, K.E = P.E
½ mv12 = mg H1
V1 = ?(2gH1)= ?( 2x9.8x10)
V1= ?196= 14 m/s
As the body loses 40% of its energy, final energy E2 =( 60/100) of initial energy
i.e. mgH2 = (60/100)mgH1
H2 =3/5 H1= (3/5)X10= 6m