Kinetic Energy Dissipation in a Colliding System

AI Thread Summary
In a collision between two hockey pucks of equal mass, puck A strikes puck B, initially traveling at 40.0 m/s and deflected at 30.0 degrees, while puck B moves at a 45.0-degree angle post-collision. The velocities of puck A and puck B after the collision are calculated to be 29.3 m/s and 20.7 m/s, respectively. The original kinetic energy of puck A is expressed in terms of its mass, leading to confusion regarding the energy dissipation calculation. The correct approach to find the fraction of kinetic energy dissipated involves using the equation 1 - (KEf - KEi) / KEi. Ultimately, the solution reveals that approximately 50% of the original kinetic energy is dissipated in the collision.
tater08
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Homework Statement



A hockey puck B rests on a smooth surface of ice and is struck by a second puck A , which was originally traveling at 40.0 m/s and which is deflected 30.0 degrees from its original direction. Puck B acquires a velocity at a 45.0 degree angle to the original direction of A . The pucks have the same mass.

what fraction of the orignal kinetic energy of puck A dissipates during the collision.

Homework Equations


(Delta K) /K
KE=0.5 mv^2

The Attempt at a Solution


i was able to solve for the velocity of both block a and b. But now i can't seem to figure out the original kinetic energy. I do not know where to go with the masses being the same.
Va=29.3 m/s
Vb=20.7
 
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You can express the kinetic energy in terms of the unknown mass "m", and go from there.
 
(Kei-Kef)/ KEi = ((1-(m1/m1+m)) KEi)/KEI = M2/m1+M2 1/ (1+1) KE should be 0.5 or 50 percent. But this is the wrong answer And I'm Totally lost. thanks for any help that i may receive.
 
I figured it out. 1-(KEf-KEi)/KEI is basically the equation to use.
 
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