I just did a lab on collisions. We used a something like an air hockey table but different. Anyways i have to determine whether or not momentum and kinetic energy are conserved. If there are no unknowns and you have the following information how would you determine if kinetic energy and momentum are conserved. Mass 1 = 0.541 kg, Mass 2 = 0.541 kg, Vi 1 = 0.33 m/s, Vi 2 = 0, Vf 1 = 0, Vf 2 = 0.3 m/s. All i need to know is if i should solve for Ekbefore first and then Ekafter or should i do Ekbefore=Ekafter that way all the masses and 1/2's cancel out. So which way is right.