The stone is thrown vertically upwards. At what moment is the resultant of the forces acting on it maximum in absolute value? is minimal? At what moment is the stone in a state of weightlessness? Note that the stone is affected by the force of air resistance.
when the stone is flying upwards, both gravity and resistance are directed downward.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.