Aristotle, Galileo & Newton's Motion | Grade 11

• This self-learning kit aids learners in comparing the motion ideas of Aristotle, Galileo, and Newton
• The kit focuses on basic Physical Science learning for grades 11, Quarter 4, Week 2
• Physics deals with object motion and its quantitative analysis
• Motion is hard to define, especially regarding interacting motions
• The self-learning kit (SLK) discusses motion concepts by Aristotle, Galileo, and Newton

Objectives

• Explain motion concepts from Aristotle, Galileo, and Newton
• Show understanding of Aristotle, Galileo and Newton's motion concepts
• Express interest in how the various concepts of motion relate to one another

Learning Competencies

• Compare Aristotelian vs. Galilean views on vertical, horizontal, and projectile motion
• Understand Galileo's inference that objects in a vacuum fall with uniform acceleration

What Happened - Sci-Quiz

• Test your knowledge of the concepts of motion

Aristotelian and Galilean Conceptions of Motion

• Current understanding of physics has gradually grown
• Philosophers have improved old ideas and critiqued weaknesses via observations
• Galileo's two contributions include the 'Law of Falling Bodies' and the 'Law of Inertia'

Law of Inertia

• Inertial motion changes only with force
• Gravity accelerates objects equally, a foundation of physics
• Galileo found the law of inertia but did not name it

Terrestrial Motion

• Alteration involves simple chemical changes

• Vertical or natural local motion includes things falling

• Horizontal and violent motion involves external force

• Celestial motion deals with movements of heavenly bodies

• Violent motion prevents natural motion and requires external forces

• To maintain motion, Aristotle believed a constant external force must be exerted

• Projectile motion is when an object moves near Earth under gravity, following a curved path

• Galileo showed this path is a parabola, becoming a line when thrown straight up

• Galileo saw projectile motion as combined horizontal and vertical motions

• Vertical motion does not affect in horizontal motion

• Horizontally launched objects hit the ground at the same time as dropped ones, following a parabolic path

• Natural philosophers based motion explanations on their philosophical viewpoints

• Galileo disproved Aristotelian motion ideas through experiments and previous ideas

Aristotelian Motion

• Natural motion is vertical, while violent motion is horizontal (projectile)

• Aristotelian: Constant force applied to maintain horizontal motion

• Aristotle's premises were largely agreed by philosophers before Galileo's time

• Scientific efforts were needed to change views and counter Aristotelian ideas

• Galileo quantified the "rate of fall" by measuring distance, time, and plotting data

• Galileo slowed the fall using ramps and arrived at significantly different conclusions

Galileo's Experiment of Falling Bodies

• Galileo found that objects fall at the same rate, regardless of weight, except when air resistance is present

• Anything that requires a force is violent motion

• Galileo allegedly proved the equal fall rate of objects and used the reductio ad absurdum

• Galileo slowed falls with ramps, deducing "rate of fall" (acceleration) by plotting position against time and varying the slope

Uniform Acceleration of Objects in a Vacuum

• Acceleration is the rate of velocity change and objects accelerate if their velocity changes

Laws of Motion with Uniform Acceleration

• Objects falling only undergo gravitational force, defined as weight (W)
• Acceleration equals gravitational acceleration
• Size, shape, and mass do not factor into the acceleration of an object
• All objects in vacuum fall equally
• Change in speed is acceleration

Galileo's Observations

• Galileo used an inclined plane to determine the relationship of time and distance traveled

• Distance depended on squared time, and the velocity increased as a ball moved down

• With an inclined plane, the speed of a rolling ball increases steadily

• The steeper the inclined plane, the greater the acceleration

• Galileo concluded falling objects have uniform acceleration

Newton's Intertia

• Galileo Galilei introduced inertia before Newton's "law of Inertia"

• A ball rolling down a plane increases speed and decreases it when rolling up due to gravity

• A ball rolling horizontally would continue moving without friction

• Motion continues unless disturbed by a push or pull

• Tendency to resist motion change is defined as inertia

• Newton based his first law of motion on Galileo's assertion

• They both implied no force is needed because the object’s inertia would keep it from changing its state of motion

• The difference is that Galileo didn't consider of force but rather focused on 'push and pull'

• Sir Isaac Newton defined the concept of force and its relation to motion

• Newton's first law says objects stay at rest or in motion unless an external force changes it

• The definition of inertia is that there is no net force acting on an object

• The object maintains constant velocity or remains at rest without external force

Sci-Activity - Performance Task

• Compare the rate of a coin and flat piece of paper falling
• Crumple the paper and repeat the experiment
• Note your results in your notebook.
• Be safe and don't perform this experiment from a dangerous height

True or False Questions

• Test your knowledge of the key facts from the summary

Compare motion concepts of Aristotle, Galileo, and Newton. This kit for Grade 11 Physical Science, Quarter 4, Week 2, explores historical perspectives on motion and introduces Galileo's vacuum acceleration inference.