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Physics: Dynamics question (Momentum + Angle)?

Hello all, I've solved this one on my own, but I'm wondering if I have to take into account the angle of inclination. I've used the basic closed system principle, in which momentum is always the same, after and before the firing of the cannon ball. All I need to know is if I need to, and if so how do I take into account the angle at which the cannon is fired? Thanks. A cannon of 300 kg mass shoots a projectile of 0.3 kg mass, at a velocity of 250 m/s, forming a 30 degree angle with the horizontal. Calculate the velocity at which the cannon is thrown backwards by the force of the shot. Friction is ignored.

Public Comments

1. Yes, you need to take account of the angle, because the mass of the earth takes on a tiny velocity in the downward direction when the cannon is fired.
2. If there is am angle of inclination then the Earth will take the vertical component of the reaction force and hence it will equal the negative vertical component of the cannonballs momentum. The cannon rolling back will equal the negative horizontal component of the cannonballs momentum. Since the Earth is so massive, the vertical velocity change will be almost but zot exactly zero.