Two pirate ships shoot identical cannon balls at each other with identical cannons at identical angles and at the same time. Their cannon balls collide at the apex of their trajectories and fall straight down. Which of the following describes the collision?
Momentum is conserved and the collision is elastic since the horizontal energy is converted to downward vertical energy.
Horizontal momentum is conserved and the collision is inelastic since the balls stuck together and/or were deformed.
Horizontal momentum is not conserved but the collision in elastic since the cannon balls struck each other.
Momentum was not conserved since the balls were accelerating downward the entire time.
None of these is correct. More information is needed to answer the question.