Vertical Motion Under Gravity vs Horizontal Motion: Key Differences

Question

Hey everyone! 👋 Let's break down vertical vs. horizontal motion in physics. It can be tricky, but I'll try to explain it simply. Think of throwing a ball straight up versus throwing it across the room. ⚽️ They seem different, right? Let's see why!

alangonzales1996 · Accepted Answer

📚 Vertical Motion Under Gravity
Vertical motion under gravity describes the movement of an object solely influenced by the Earth's gravitational force. Imagine throwing a ball straight up in the air. Once released, the only force acting upon it (ignoring air resistance) is gravity, causing it to slow down, stop momentarily at its highest point, and then accelerate downwards.

📚 Horizontal Motion
Horizontal motion, in its simplest form, describes movement in a straight line at a constant velocity. If we ignore external forces like friction and air resistance, an object in horizontal motion will continue moving at the same speed and direction forever (Newton's First Law). Think of a puck sliding across perfectly smooth ice.

📊 Vertical vs. Horizontal Motion: A Comparison

Feature
      Vertical Motion Under Gravity
      Horizontal Motion

Force Acting
      Gravity (constant downward acceleration)
      Ideally, no force (constant velocity if friction is negligible)

Acceleration
      Constant, $a = -g \approx -9.8 m/s^2$ (downwards)
      Zero (assuming no other forces)

Velocity
      Changes continuously due to gravity; decreases upwards, increases downwards.
      Constant (assuming no other forces)

Equations of Motion
      Uses kinematic equations with constant acceleration due to gravity: e.g., $v = u + at$, $s = ut + \frac{1}{2}at^2$, $v^2 = u^2 + 2as$
      Simple equations like distance = speed x time, $d = vt$

Trajectory
      Parabolic path (if there's an initial horizontal velocity component, like projectile motion) or straight line (if thrown straight up/down)
      Straight line (assuming constant velocity)

Example
      A ball thrown vertically upwards, a dropped object.
      A puck sliding on ice (ideally frictionless), a car moving at constant speed on a straight, level road.

🚀 Key Takeaways

🍎 Gravity's Influence: Vertical motion is always affected by gravity, leading to changing velocity.
    📏 Constant Velocity: Horizontal motion, in ideal scenarios, maintains a constant velocity.
    💡 Equations Matter: Different equations are used to describe each type of motion due to the presence or absence of acceleration.
    🧪 Real-World Application: Understanding these differences is crucial for analyzing projectile motion and other physics problems.

Vertical Motion Under Gravity vs Horizontal Motion: Key Differences

1 Answers

📚 Vertical Motion Under Gravity

📚 Horizontal Motion

📊 Vertical vs. Horizontal Motion: A Comparison

🚀 Key Takeaways

Join the discussion

Feature	Vertical Motion Under Gravity	Horizontal Motion
Force Acting	Gravity (constant downward acceleration)	Ideally, no force (constant velocity if friction is negligible)
Acceleration	Constant, $a = -g \approx -9.8 m/s^2$ (downwards)	Zero (assuming no other forces)
Velocity	Changes continuously due to gravity; decreases upwards, increases downwards.	Constant (assuming no other forces)
Equations of Motion	Uses kinematic equations with constant acceleration due to gravity: e.g., $v = u + at$, $s = ut + \frac{1}{2}at^2$, $v^2 = u^2 + 2as$	Simple equations like distance = speed x time, $d = vt$
Trajectory	Parabolic path (if there's an initial horizontal velocity component, like projectile motion) or straight line (if thrown straight up/down)	Straight line (assuming constant velocity)
Example	A ball thrown vertically upwards, a dropped object.	A puck sliding on ice (ideally frictionless), a car moving at constant speed on a straight, level road.