1. The problem statement, all variables and given/known data A particle (m1) w/mass 0.080 kg has an initial velocity of 50m/s in the +x-direction and collides with a particle (m2) w/mass 0.060 kg with an initial velocity of 50m/s in the +y-direction. After the collision, particle (m1) and particle (m2) are stuck together and travel at some unknown velocity with an unknown angle. What is the lost in kinetic energy due to the collision? 2. Relevant equations Initial Linear Momentum = Final Linear Momentum delta K = Kf - Ki 3. The attempt at a solution What I did was set-up a x- and y-component of the conservation of linear momentum to solve for the final velocities in their respective components. I know that the velocity that results of the two particles being stuck together after the collision is the "final" velocity which would be responsible for the final kinetic energy right? Beyond this, I do not know how to solve for the lost in kinetic energy? Could someone please tell me how to solve for this? Thanks.