1. The problem statement, all variables and given/known data So theres a particle of mass 4u that strikes another particle of mass 196u. The collision is elastic. What percentage of its original kinetic energy has the moving particle lost? 2. Relevant equations m1v1o + m2v2o = m1vf + m2v2f K1o + K2o = K1f + K2f 3. The attempt at a solution so because its elastic, the kinetic energy total will not change, thus the Kt= Kft. V2o will be zero, because its not moving. It is possible to set the two equations, one for momentum and the other for Kinetic Energies, equal to each other and cancel out v2f. This helps reduce the problem to 24Vo^2 + VoVf = 25Vf^2 how would having this equation help me find the percentages? Am I on the right track at all?