Car Crash Collision - Calculating Velocity

AI Thread Summary
The discussion focuses on calculating the final velocity of a car after a collision using the principles of conservation of momentum. A 480kg car traveling at 14.4m/s collides with a 570kg car moving at 13.3m/s, which then moves at 17.9m/s post-collision. The calculations confirm that the collision is elastic, leading to the equation m1v1 + m2v2 = m1v1f + m2v2f. The derived final velocity of the first car after the collision is 8.94m/s. The solution appears to be correct based on the provided calculations.
StephenDoty
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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?
 
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Looks right to me.
 

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