Boxcar A, with mass of 1500 kg, is travelling at 25 m/s to the east. Boxcar B has a mass of 2000 kg, and is initially at rest. The box cars collide in elastically and move together after they get stuck. What is their combined velocity?

Answer 1

MV+MV=(M+M)V
(1,500Kg)(25m/s)+(2,000Kg)(0)= (2000Kg+1500Kg)V
37,500=3,500V
37,500/3,500=3,500/3,500V

V=1.07m/s

Answer 2

10.7m/s