Q 11.     Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m s-1 before the collision during which they stick together. What will be the velocity of the combined object after collision?

Answers (1)
S Sanket Gandhi

The velocity of the combined mass after the collision will be zero.

This can be found using the law of conservation of the momentum :

                                               m_1u_1\ +\ m_2u_2\ =\ (m_1\ +\ m_2)v

or                                              mu\ +\ m(-u)\ =\ (2 m)v

or                                                                    2mv\ =\ 0

Thus                                                                      v\ =\ 0