Two Hockey Puck Collision: Calculating Speed After Impact

AI Thread Summary
Two hockey pucks of equal mass collide, with one initially moving at 5.4 m/s and the other at rest. After the collision, the pucks move at angles of 33 and 46 degrees relative to the initial puck's direction. The correct speeds after the collision are determined to be 3 m/s and 4 m/s. Momentum conservation is crucial, as it is a vector quantity, requiring the final momentum to equal the initial momentum in both magnitude and direction. The use of vector analysis, such as the sine law, helps in solving for the final speeds.
Morhas
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Homework Statement


Two hockey puck of equal mass undergo a collision on a hockey rink. One puck is initiall at rest while the other is moving with a speed of 5.4m/s. After the collision, the velocities of the pucks make angles of 33 and 46 (degrees) relative to the initial velocity of the moving puck. Determine the speed of each puck after the collision.


Homework Equations





The Attempt at a Solution



We have tried several failed approaches. The correct answer is 3m/s and 4m/s. What is confusing us is that the momentum should be conserved. So the sum of the two final momentums should be that of the initial momentum. Thanks in advance,
 
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Bump. Can anyone explain this? My friend and I have a test tommorow and we still don't see how this is possible. Thanks.
 
Morhas said:
Bump. Can anyone explain this? My friend and I have a test tommorow and we still don't see how this is possible. Thanks.
It is conserved. momentum is a vector quantity. The initial momentum is to the right. The final momentum, the vector sum of the 2 pucks after the collison, must be equal to and in the same direction as the initial momentum.
 
Ahhh I see. So What I've done is drawn the two vectors as two sides in a triangle, with the third side being the initial momentum vector. Then I solved with sin law. Thanks for the post!
 

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