Collisions and changing frame of reference?

AI Thread Summary
In the discussion about collisions and changing frames of reference, a scenario involving two trolleys colliding is analyzed. The 6.0 kg trolley moving at 6.0 m/s collides with a 2.0 kg trolley moving at 2.0 m/s, and the collision is elastic. The user attempts to calculate the post-collision speeds using the provided formulas but arrives at incorrect results, suggesting a misunderstanding in the application of the equations. The mention of "changing frame of reference" indicates a potential confusion regarding how relative velocities affect the outcome. Clarification on the calculations and the concept of frames of reference is needed to resolve the discrepancies.
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collisions and "changing frame of reference?"

Homework Statement


A 6.0Kg trolley moving at 6.0 m/s right overtakes and collies with a 2kg trolley moving 2m/s right in the same direction on the same track. The collision is cushioned by a perfectly elastic bumper attached to one of the trolleys.

A) what is the speed and direction of each trolley after the collision?

B) What is the maximum amount of potential energy stored in the bumper during the collision?

Homework Equations


V1' = v1 (m1 - m2) / ( m1 + m2 )

V2f = 2*m1v1 / (m1+m2)

The Attempt at a Solution



for A) I tried that by substituting in values from the question and It gave me 3m/s and 9m/s... yet the answer says 4m/s and 8 m/s... am I doing anything wrong? =/

**my friend said something about change frame of reference...**

didn't start B yet because I didn't get A yet =/
 
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