1. The problem statement, all variables and given/known data A hockey puck moving along the +x axis at 0.5 m/s collides into another puck that is at rest. The pucks have equal mass. The first puck is deflected 37degrees below the +x axis and moves off at 0.36 m/s. Find the speed and direction of the second puck after the collision. 2. Relevant equations 1/2*m_a*v_ai^2 + 1/2*m_b*v_bi^2 = 1/2*m_a*v_af^2 + 1/2*m_b*v_bf^2 m_a*v_ai + m_b*v_bi = m_a*v_af + m_b*v_bf 3. The attempt at a solution For part1, I am using the condensed formula of: v_ai^2 = v_af^2 + v_bf^2 since the masses are equal and the second puck starts at rest, which gives me v_bf = .3496 (says it is incorrect) For part2, I know to separate the x-component and y-component to get (condensed again): x: 0.5 = (.36)(cos37) + (v_bf)(cos[unknown]) y: 0 = (.36)(sin37) + (v_bf)(sin[unknown]) I could solve for the unknown angle if I knew v_bf. Can anyone help me find what I am doing wrong?