Car Crash Collision - Calculating Velocity

[StephenDoty]

Question:
A 480kg car moving at 14.4m/s hits from behind another car moving at 13.3m/s in the same direction. If the second car has a mass of 570kg and a new speed of 17.9m/s what is the velocity of the first car after collision?

Since there is a velocity for one car after the collision and the question asks for the other car's velocity after the collison this collision must be elastic.
Thus
m1v1 + m2v2 = m1v1f + m2v2f
480*14.4 + 570*13.3 = 480v1f + 570*17.9
14493N = 480v1f + 10203N
4290N = 480v1f
8.94m/s = v1f


Is this right?

 

[Snazzy]

Looks right to me.

 

[Moetasim]

Yes, your approach and calculation are correct. The final velocity of the first car after the collision is 8.94m/s. However, it is important to note that this calculation assumes an idealized situation where there is no external force acting on the cars and there is no loss of energy during the collision. In real-world scenarios, there may be other factors that can affect the final velocity of the cars after a collision.