How Do You Calculate the Velocity of Wreckage After a Head-On Collision?

AI Thread Summary
To calculate the velocity of wreckage after a head-on collision, the equation vf = (m1*v1 + m2*v2) / (m1 + m2) is used, where m represents mass and v represents velocity. In this scenario, Vehicle 1 (1245 kg) is traveling south at 20.0 m/s, and Vehicle 2 (910 kg) is traveling north at 26.0 m/s. The key error in the attempted solution was not accounting for the direction of the velocities, which affects the final result. Correctly applying the equation with directional values yields a final velocity of 0.58 m/s for the wreckage, aligning with the lecturer's answer. Accurate direction consideration is crucial in such calculations.
Chica1975
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Homework Statement



2 vehicles made a totally inelastic head-on collision on the highway. Vehicle 1 of mass 1245kg was traveling southward at 20.0m/s. Vehicle 2 of mass 910kg was traveling northward at 26.0m/s. what was the velocity of the tangled wreckage?


Homework Equations


vf= ma1va1+mb2vb2/ma+mb


The Attempt at a Solution


I plugged in the information as per the equation above, however, I keep getting a different answer to that of my lecturer - I get 22.5336 m/s
The correct answer is 0.58 m/s

PLEASE HELP WHERE AM I GOING WRONG?
 
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you have to take into consideration the direction of their velocity. You did everything right but did not take into account their direction of motion. I used what you gave and i got your lecture answer
 

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