Inelastic Collisions

These collisions are even easier to understand and analyze than elastic collisions. The whole solution is developed from

$$P_{i,\rm tot} = m_1v_{1i} + m_2v_{2i} = (m_1 + m_2)v_f = (m_1 + m_2)v_{\rm cm} = P_{f,\rm tot}$$ (4.63)

From this relation you can easily find $v_f$ in any number of dimensions, and answer any related questions. See the example below (ballistic pendulum).