Finding the Mass of a Puck in a 2-Dimensional Collision

[SwAnK]

having trouble with this problem in my textbook

two pucks collide, puck A has a mass of 0.32kg, and an initial velocity of 0.04 m/s [54 N of E], and a final velocity of 0.034 m/s [N]
puck B's mass is unknown but has an initial velocity of 0.038 m/s [S of W] and a final velocity of 0.028 m/s [46.5 N of E]. Puck B's mass needs to be found.

Wheni tried it i used components but i did not get the right answer, the answer in the back of the book is 0.22kg. Does anyone else get this answer? if so could you explain how?? thanx.

 

[neurocomp2003]

what equations did you use...i'm assuming pure elastic?

 

[SwAnK]

yeah i assumed that it was pure elastic, the equation used was..

(m1x)(v1x) +(m2x)(v2x) = (m1x)(v1fx) +(m2x)(v2fx)

(m1y)(v1y) +(m2y)(v2y) = (m1y)(v1fy) +(m2y)(v2fy)

 

[Pyrrhus]

Could you show me your complete procedure?

 

[neurocomp2003]

try using the conservation of Energy rather than momentum...cuz with teh Cons of Mom...it'd be best if you showed those angles...sorry lazy to draw it out myself.

 

[SwAnK]

bah! sorry for wasting your time, i measured the one angle wrong it was 45 instead of 54! thanks for your time though, with that change the problem does work out to the solution in the back.