Imagine that you are an observer in space (so you are in an inertial system), when the cannon (located on the equator) fires a cannonball in north direction. What does the trajectory of the cannonball look like from your perspective? Is it a straight line (that would mean that the cannonball is not affected by Earth's rotation) or something like a spiral?
The Attempt at a Solution
I think that, since the only real force acting on the body is the gravitational force, the trajectory is like a spiral. I also know that no Coriolis force exists in my inertial frame of reference. Am I right?