1. The problem statement, all variables and given/known data A hockey puck of mass 0.16kg has initial velocity of 2.0m/s[E] and collides with another puck that is initially at rest, has mass of 0.17kg. Once they collide the first puck travels 1.5m/s[N 31 E]. Find final velocity of second puck. 2. Relevant equations 3. The attempt at a solution I keep getting an answer that does not match with solutions. So I first drew it out then made a triangle that does is not a right angle, so I decided to use cosine law. I am aware that my total momentum is 0.32 kg m/s because PT=PT' ... PT= (0.16)(2) =0.32 kg m/s I also figured out my P1 P1= (0.16)(1.5) = 0.24 kg m/s I set my triangle up to have a 59° because 90°-31°. Now I use cosine law to find opposite side of my 59°. a=√(0.32)2+(0.24)2-2(0.24)(0.32)cos59 P2= 0.2844 kg m/s Now I plug this into P=mv V = 0.2844/0.17 V = 1.7m/s [E 46 S] Did I do something wrong??