Answer:
the final velocity of the combined cars after collision = +1.5 m/s
The plus sign to indicate that the velocity is directed in the same direction as the initial velocity of train car 1.
Explanation:
Given
Mass of train car 1 = 10,000 kg
Initial velocity of train car 1 = 3.0 m/s
Mass of train car 2 = 10,000 kg (they said the two train cars were similar)
Train car 2 was initially at rest, initial velocity of train car 2 = 0 m/s
Then it is given that the train cars combine (stick together) after collision, meaning the collision was inelastic.
Let the final velocity of the combined cars be v
This question can be solved using the laws of the conservation of Momentum.
Momentum before collision = Momentum after collision
Momentum before collision = (Momentum of train car 1 before collision) + (Momentum of train car 2 before collision)
= (10000)(3) +(10000)(0) = 30,000 kgm/s
Momentum after collision = (10,000 + 10,000)(v) = (20000v) kgm/s
Momentum before collision = Momentum after collision
30000 = 20000v
v = (30000/20000) = 1.5 m/s.
Hence, the final velocity of the combined cars after collision = +1.5 m/s (plus sign to indicate that the velocity is directed in the same direction as the initial velocity of train car 1)
Hope this Helps!!!
