Forces at Play
* Gravity: The only force acting on a projectile (ignoring air resistance) is gravity. Gravity acts *vertically downwards*.
* No Horizontal Force: There's no force acting on the projectile horizontally.
Impact on Velocity
* Vertical Component: Gravity constantly pulls the projectile downwards, causing its vertical velocity to increase in the downward direction. This means the vertical velocity changes over time.
* Horizontal Component: Since there's no force acting horizontally, the projectile continues moving at a constant horizontal speed. There's no change in its horizontal velocity.
Analogy
Think of throwing a ball straight up. As it goes up, gravity slows it down until it momentarily stops at the highest point. Then, gravity pulls it back down, making it speed up. The same principle applies to the vertical component of a projectile's motion.
Important Notes
* Air Resistance: In real-world scenarios, air resistance plays a role. It acts in the opposite direction of the projectile's motion, slowing it down both vertically and horizontally.
* Neglecting Air Resistance: In introductory physics, air resistance is often ignored to simplify calculations and focus on the fundamental principles of motion.
