What is the combined speed of linked model train cars with different masses?

AI Thread Summary
The discussion centers on calculating the combined speed of two linked model train cars with different masses. A 230 g car moving at 0.50 m/s links with a stationary 430 g car. The correct method involves using conservation of momentum to find the speed after they connect. Participants note that an incorrect speed of 0.17 m/s may stem from unit conversion errors. Accurate calculations are essential for determining the final speed of the linked cars.
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A model-train car of mass 230 g traveling with a speed of 0.50 m/s links up with another car of mass 430 g that is initially at rest. What is the speed of the cars immediately after they have linked together?
 
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i have been working online for it but it is coming out wrong, i get .17
 
maybe you forgot your units?
 

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