Question

jordan has a mass of 65kg and carlos has a mass of 78.0kg. jordan is running at 5.75m/s when he is tackled by carlos who is running in the opposite direction. after the collision of both players are at rest. calculate their velocity before the collision.

Answer 1

Given

mj = 65 kg

mc = 78 kg

voj = 5.75 m/s

after collision

vfj = vfc = 0 m/s

Procedure

The law of momentum conservation can be stated as follows. For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.

$\begin{gathered} p_o=p_f \\ m_jv_{0j}-m_cv_{0c}=0 \\ m_jv_{0j}=m_cv_{0c} \\ v_{0c}=\frac{m_jv_{0j}}{m_c} \\ v_{0c}=\frac{65kg*5.75m/s}{78kg} \\ v_{Oc}=4.8m/s \end{gathered}$

The velocity before the collision would be 4.8m/s