Question

A 20 g ball of clay traveling east at 2 m/s collides with a 30 g ball of clay traveling 30° south of west at 1 m/s. What is the velocity of the resulting blob of clay?

Answer 1

Masses m = 20 g

           M = 30 g

Initial velocities u = 2 i

                       U = 1x cos 30 ( -i) + 1 x sin 30 ( -j)

                           = -0.866 i -0.5 j

Let the velocity of the resulting 50 g blob of clay be v

From law of conservation of momentum ,

mu+ MU = ( m+ M) v

40 i -25.98 i - 15 j = 50 v

14.01 i - 15 j = 50 v

v = 0.2803 i - 0.3 j

Speed of the resulting 50 g clay v = √[ 0.2803 ² + (-0.3) ² ]

                                                    = 0.4105 m / s