A ball of mass m hits the floor with a speed v making an angle of incidence θ with the normal. The coefficient of restitution is e. The speed of reflected ball and the angle of reflection of the ball will be
v' = v, θ = θ'
The coefficient of restitution is a number which indicates how much kinetic energy ( energy of motion ) remains after collision of two object.
The parallel component of velocity of the ball remains unchanged. This gives
v' sinθ = v sinθ .... (i)
For the components normal to the floor, the velocity of separation = v' cosθ
Hence v' cosθ' = e v cosθ .....(ii)
From equations (i) and (ii)
and tanθ' =
For elastic collision, e = 1, so that
θ' = θ and v' = v