Horizontal Velocity vs Vertical Velocity in Projectile Motion: What's the Difference?

Question

Hey everyone! 👋 Ever get confused about the difference between how fast something moves sideways versus how fast it moves up and down when you're talking about projectile motion? It's a pretty important concept in physics. Let's break it down in a simple way to understand horizontal vs. vertical velocity in projectile motion. We'll look at what each one means and how they affect the path of a projectile. Ready to dive in? 🤓

michaeldawson1988 · Accepted Answer

📚 Horizontal Velocity: The Sideways Speed
Horizontal velocity refers to the speed of an object moving parallel to the ground. In projectile motion (like throwing a ball), assuming we ignore air resistance, the horizontal velocity remains constant throughout the object's flight. This is because there's no horizontal force acting on the projectile after it's launched.

📚 Vertical Velocity: The Up-and-Down Speed
Vertical velocity, on the other hand, describes the speed of an object moving up or down. This velocity is constantly changing due to gravity. When you throw a ball upwards, its vertical velocity decreases until it reaches its highest point, where the vertical velocity is momentarily zero. Then, as the ball falls back down, its vertical velocity increases in the downward direction.

📝 Horizontal vs. Vertical Velocity: A Detailed Comparison

Feature
      Horizontal Velocity
      Vertical Velocity

Definition
      The speed of an object moving parallel to the ground.
      The speed of an object moving up or down.

Effect of Gravity
      Negligible (assuming no air resistance). Remains Constant.
      Significant. Changes constantly due to gravity ($g = 9.8 m/s^2$).

Change Over Time
      Ideally, no change. Remains constant throughout the projectile's flight.
      Changes continuously. Decreases on the way up, increases on the way down.

Velocity at Max Height
      Equal to the initial horizontal velocity.
      Zero. Momentarily stops moving vertically upwards at its peak.

Mathematical Representation
      $v_x = v_{0x}$ (where $v_{0x}$ is the initial horizontal velocity)
      $v_y = v_{0y} - gt$ (where $v_{0y}$ is the initial vertical velocity, $g$ is the acceleration due to gravity, and $t$ is time)

✨ Key Takeaways

➡️ Independence: Horizontal and vertical velocities are independent of each other. One doesn't directly affect the other.
   🍎 Gravity's Influence: Gravity only affects the vertical velocity, causing it to change over time.
   📈 Constant vs. Changing: Horizontal velocity is constant (ignoring air resistance), while vertical velocity changes constantly.
   📐 Vector Components: The overall motion of a projectile can be analyzed by breaking it down into these horizontal and vertical components.

Horizontal Velocity vs Vertical Velocity in Projectile Motion: What's the Difference?

1 Answers

📚 Horizontal Velocity: The Sideways Speed

📚 Vertical Velocity: The Up-and-Down Speed

📝 Horizontal vs. Vertical Velocity: A Detailed Comparison

✨ Key Takeaways

Join the discussion

Feature	Horizontal Velocity	Vertical Velocity
Definition	The speed of an object moving parallel to the ground.	The speed of an object moving up or down.
Effect of Gravity	Negligible (assuming no air resistance). Remains Constant.	Significant. Changes constantly due to gravity ($g = 9.8 m/s^2$).
Change Over Time	Ideally, no change. Remains constant throughout the projectile's flight.	Changes continuously. Decreases on the way up, increases on the way down.
Velocity at Max Height	Equal to the initial horizontal velocity.	Zero. Momentarily stops moving vertically upwards at its peak.
Mathematical Representation	$v_x = v_{0x}$ (where $v_{0x}$ is the initial horizontal velocity)	$v_y = v_{0y} - gt$ (where $v_{0y}$ is the initial vertical velocity, $g$ is the acceleration due to gravity, and $t$ is time)