Q.
A sphere of mass m moving with a constant velocity u hits another stationary sphere of the same mass. If e is the coefficient of restitution, then the ratio of velocities of the two spheres after collision (v2v1) will be
Conservation of momentum (gives) mu+0=mv1+mv2 ⇒v1+v2=u ...(i)
Newton's experimental formula, v1−v2=−e[u1−u2] gives v1−v2=−eu ...(ii)
From Eqs. (i) and (ii), we get v1=2(1−e)u v2=2(1+e)u ∴v2v1=1+e1−e