Question

A ball is dropped on a horizontal surface from height H if it rebounds to height H by 2 after first collision then coefficient of restitution between ball and surface is​

Answer 1

Explanation:

According to the  data given, the initial speed of the ball be

                                              u = √ 2 g h

which is before the collision.

And will change after collision as

                                            v = √ 2 g h/ 2.

Thereby as we know that coefficient of restitution is the factor which changes the initial velocity, we have the formula as v = e x u where e is the coefficient of restitution.

Thereby,

                                    √ 2 g h/ 2 = e √ 2 g h

                                      => √  g h = e x √ 2 g h

                                      => e = 1 / √ 2

                                      => e = 0.707.