Question

An ice skater at rest on ice catches a dance partner moving 2.5 m/s during a performance. The ice skater has a mass of 68 kg and the dance partner has a mass of 54 kg. What is the speed of the ice skater and dance partner after the collision?

Answer 1

$\begin{gathered} For\text{ ice }skater \\ m_i=68\text{ kg} \\ \text{For }partner \\ m_p=54\text{ kg} \\ v_p=2.5\text{ m/s} \\ \text{Velocity after }collision=v_{i+p}=? \\ v_{i+p}=\frac{m_pv_p}{m_p+m_i} \\ \\ v_{i+p}=\frac{(54\text{ kg})(2.5\text{ m/s})}{54\text{ kg}+68\text{ kg}} \\ \\ v_{i+p}=\frac{135\text{ kgm/s}}{122\text{kg}} \\ v_{i+p}=1.1\text{ m/s} \\ \text{The spe}ed\text{ after collision is }1.1\text{ m/s} \end{gathered}$