Newton laws Watch
Acceleration is directly proportional to Unbalanced Force
Acceleration is inversely proportional to it's Mass
I guess for an object to be in a motion as in angular motion , we need an unbalanced force as stated by Newton's 1st law (objects don't accelerate unless an unbalanced force is applied.. if unbalanced forces = 0 , then it would move at constant velocity or be at rest ).
So unbalanced force creates the velocity as in angular motions ( or force can be used instead of velocity when speaking)
When in angular motion, the object has a vertical component and a horizontal component.
The vertical component is under W=mg (which is almost F=ma)( g=9.8 m/s^2)
So it is under Newton's 2nd law as I stated at first!
Also, the horizontal component has no acceleration.
This is why the horizontal component is the same throughout the flight.
It continues with constant velocity according to Newton's 1st law of motion as no unbalanced force acts horizontally