ME Sci 11_12 Q4 1101 PS

Lesson Overview

  • Title: Aristotelian and Galilean Views of Motion

Learning Competencies

  • Compare and contrast the Aristotelian and Galilean conceptions of:

    • Vertical Motion

    • Horizontal Motion

    • Projectile Motion

  • Meet the DepEd learning competency S11/12PS-IVc-46.

Learning Objectives

  • Differentiate between Aristotle's and Galileo's conceptions of motion.

Introduction to Motion

  • All actions performed by a body involve motion.

  • Motion is an object's change in position with respect to time.

Historical Context

  • Early scientists and philosophers conducted rigorous experiments, observations, and reasoning to understand motion.

  • The fundamental understanding of motion began with figures like Aristotle and Galileo.

Aristotle's Views on Motion

General Observations

  • Based his ideas on observations accepted for many years.

Types of Motion

  1. Natural Motion

    • Occurs when an object moves and returns to its natural state.

    • Example: Smoke rises because it resembles air; earthy objects return to the ground.

  2. Violent Motion

    • Occurs when an external force is applied (e.g., pushing or pulling).

    • No motion without a mover in contact.

Vertical Motion

  • Depend on the elemental composition:

    • Fire and Air: rise upward.

    • Earth and Water: fall downwards, as they have a natural resting place.

    • Heavier objects were thought to fall faster than lighter ones.

Horizontal Motion

  • Caused by a force called impetus.

  • Example: An arrow moves forward due to air resistance once released from the bow.

Projectile Motion

  • Projectiles move towards the ground after being propelled, remaining horizontal until then.

Galileo's Views on Motion

General Observations

  • Challenged Aristotelian theories with empirical evidence.

Vertical Motion

  • Believed all objects fall due to gravity, regardless of weight.

  • In a vacuum (absence of air resistance), all objects fall simultaneously regardless of weight.

  • Noted resistance in fluids can slow down falling objects.

Horizontal Motion

  • An object in motion continues in motion if unimpeded.

  • No external force is necessary to maintain motion on a flat, infinite surface.

  • In reality, friction will slow down motion over time.

Projectile Motion

  • Described as a combination of vertical and horizontal motions, termed compound motion.

  • The trajectory of a projectile is curved due to the influence of gravity.

Key Points

  • Aristotle:

    • Distinguishes natural vs. violent motion.

    • Vertical motion is element-dependent.

    • Horizontal motion caused by impetus and affected by external forces.

    • Projectiles remain level until gravity affects them.

  • Galileo:

    • Vertical motion is determined by gravity, not weight.

    • Horizontal motion persists without external forces.

    • Projectile motion comprises independent vertical and horizontal components, following a curved path (trajectory).

Understanding Exercises

Identify Motion Types

Analyze scenarios:

  1. A paper falling – Natural Motion

  2. Soccer player kicking a ball – Violent Motion

  3. A glass of water spilling – Violent Motion

True or False Statements

  1. Compound motion is the same as horizontal motion. – False

  2. Objects sink in water due to being lighter than the water's force. – False

Bibliography

  • Cutnell, John D., and Kenneth W. Johnson. Physics. New York: John Wiley & Sons, Inc., 1995.

  • Gerbis, Nicholas. "10 Things We Thought Were True Before the Scientific Method." How Stuff Works, July 17, 2014.

  • Mulligan, Joseph F. Introductory College Physics. New York: McGraw-Hill Book Company, 1985.