Energy problem with inelastic collision

AI Thread Summary
In an inelastic collision involving a railroad car and three additional cars, the initial kinetic energy is calculated based on their respective masses and velocities. The first car, weighing 2.50x10^4 kg and moving at 4.00 m/s, collides with three identical cars moving at 2.00 m/s, resulting in a final velocity of 2.50 m/s after the collision. The change in kinetic energy is crucial for determining the energy transformed into internal energy during the collision. The approach using the equation ΔE=ΔK+ΔU is considered, but the user expresses uncertainty about its application. Ultimately, the change in kinetic energy should equal the work done, which corresponds to the change in internal energy.
mickellowery
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Homework Statement


A railroad car with a mass 2.50x10^4 kg moves at 4.00 m/s. It collides and connects to 3 more cars each with the same weight as the first, they're moving 2.00 m/s. After they connect the final velocity was 2.50 m/s. How much energy is transformed into internal energy in the collision?


Homework Equations


I was trying to use \DeltaE=\DeltaK+\DeltaU=-fkd. I wasn't sure if this was the right approach, and I think maybe I'm setting everything up wrong because I'm not coming up with the right answer.


The Attempt at a Solution

 
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mickellowery said:

Homework Equations


I was trying to use \DeltaE=\DeltaK+\DeltaU=-fkd. I wasn't sure if this was the right approach, and I think maybe I'm setting everything up wrong because I'm not coming up with the right answer.

The change in kinetic energy should give the work done which should be the same as the change in internal energy.
 

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