Loss of momentum in supposedly isolated inelastic collsion?

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The discussion centers on a lab experiment involving an inelastic collision between two gliders on an air track, where the calculated momentum before and after the collision appears inconsistent. The participant calculated initial momentum as .072 N*s and final momentum as .028 N*s, indicating a loss of momentum. They question whether this discrepancy could be due to energy lost in vibrations during the impact. The participant notes that, given equal masses, the final velocity should be half of the initial velocity of the moving glider. The conversation highlights the importance of accurate velocity measurements in momentum calculations.
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I may have made a mistake in calculating, but I just finished lab homework where my calculated momentum was different before and after an inelastic collsion. Is it possible that momentum was lost in the vibration of the impact or something?

The experiment placed two gliders on a level air track (isolated system) and one glider was pushed into a second one that was station.

here are my values:
m for both gliders = .2014 kg
v1i = .3576 m/s (after the push)
v2i = 0.000 m/s
vf = .0716 m/s

with all that subbed into the conservation of momentum equation for inelastic collsions, i got .072 N*s for before the collision, and .028 N*s for after. That doesn't =0!
 
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It looks like an error in one of the velocities. Since both masses are the same, the final velocity immediately after impact should be half the velocity of the moving object just before impact.
 

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