1. Forces Acting on a Projectile:
* Gravity: The only force acting on a projectile once launched is gravity, which acts vertically downwards.
* Air Resistance: We'll ignore air resistance for now, as it complicates things. In reality, air resistance will affect both horizontal and vertical motion.
2. Horizontal Motion:
* No Force: Since gravity acts vertically, there is no force acting horizontally on the projectile.
* Newton's First Law: According to Newton's First Law of Motion, an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction *unless acted upon by an unbalanced force*.
* Constant Velocity: As there is no horizontal force, the horizontal velocity of the projectile remains constant throughout its flight.
3. Vertical Motion:
* Gravity's Influence: Gravity exerts a constant downward force on the projectile, causing its vertical velocity to change.
* Acceleration: This constant force results in a constant downward acceleration (due to gravity, approximately 9.8 m/s²).
* Changing Velocity: The vertical velocity initially decreases as the projectile goes up (slowing down), then increases as it falls back down (speeding up).
In Summary:
The horizontal component of a projectile's velocity remains constant because there's no horizontal force acting on it. The vertical component changes due to the constant downward force of gravity.
