Question
Please help. (Right-click the image and select view)
As shown in the figure below, cars #1 and #2 are sliding across a horizontal friction less surface. The cars are equipped with a coupling arrangement similar to the one on railroad cars. Car #1 overtakes car #2 and they have a totally in elastic collision and become coupled together. You know the mass of each car; m1 = 16.5 kg and m2 = 47.0 kg. In addition, you are provided with the following graph, which shows the momentum of car #1 before, during and after the collision. Determine the velocity of car #2 before the collision.
Explanation / Answer
For car 1
Before collision P = 100 = m*v = 16.5*v => v=6.06m/sec
After collision P =40 = 16.5*V => V = 2.4242 m/sec
Apply momentum conservation
16.5*6.06+47*V2 = (16.5+47)*2.4242 => V2 = velocity of car 2 before collision = 1.1478m/sec ANS