Some particles are created via collisions. for instance, pions are created via collisions
with high energy protons and carbon, which releases neutrons and pions (which they
themself, decay into muons).
suppose two particles with momenta of p1 = (3,-1, 0, 0) kg and p2 = (2, 1, 1, 0) kg collide.
three particles are created as a result from this collision, two of which have momenta of
p3 = (1, 1, 0, 0) kg and p4 = (1,-0.5, 0, 0) kg, determine the four momentum, energy, rest
mass and three velocity of the third daughter particle.