,u2=0 Coefficient of restitution, e = 0.5 Let v1 and v2 be their respective velocities after collision. Applying the law of conservation of linear momentum, we get m1u1+m2u2=m1v1+m2v2 ∴m×2+2m×0=m×v1+2m×v2 or 2m=mv1+2mv2 or 2=(v1+2v2).......(i) By definition of coefficient of restitution, e=
v2−v1
u1−u2
or e(u1−u2)=v2−v1 0.5(2−0)=v2−v1 1=v2−v1........(ii) Solving equations (i) and (ii), we get v1=0