What does air resistance directly and indirectly affect on projectile shot at an angle and shot horizontally?

Question

I think that it directly affect the net force and indirectly affect the acceleration, range, maximum height and the launch velocity.

Answer 1

In general, air resistance causes a drag force on the body moving through the air.  The magnitude of the drag force is proportional to the square of the speed of the body in the air, and its direction is exactly opposite to the direction of the velocity vector.  So whether a body is moving horizontally, vertically, or at some inclination, the drag force will be exactly opposite that direction.

 

Drag force is part of the net force, so it affects acceleration.  Since drag depletes energy from the body, it reduces maximum range and maximum height.  But it does not impact launch velocity.  That is an initial condition set by the launcher, independent of the environment into which the body is launched.  After launch, with the body emerging with some initial velocity, then drag begins to deplete the body of energy.