Determine for each of the following statements whether it is always true or can be false. Two objects of different masses but moving at the same velocity have different momentum. -this should be true because p=mv and if there are different v then the p should be different. Kinetic energy is conserved in an elastic collision. -true Momentum of a system may be conserved even when mechanical energy is not. -false In an elastic collision the momentum is conserved. -true In a perfectly inelastic collision, all the kinetic energy of the objects involved in the collision is lost. -true These are the answers I believe to be true. Does anyone have any idea why at least one of them is wrong?