2 In what direction did the ship move? Why do you think so? Krishna Gopal Shrivestava of India set an unofficial world record in 1999 by pulling a ship with a mass of 244,000 kg with his teeth. We can use this feat to learn about force, mass, and acceleration.How would a small rowboat be different if Shrivestava pulled it rather than a large ship?In what direction did the ship move? Why do you think so?When Shrivestava stopped pulling, did the ship stop moving? Explain.You may wish to locate a picture of this event and add it to this slide.
3 Famous Scientists The Laws of Motion Great ideas on motion!
4 Section 1: The First Law of Motion Objectives:Define Newton’s first law of motion.Explain how inertia and mass are related.
5 WRONG!! Aristotle (300 B.C.) Greece His ideas were popular for ~2,000 years.Now, his ideas are obsolete.2,000 years of false knowledgeWhat Aristotle said:Heavier objects fall faster than lighter onesEarth is the center of the universeAll motion on Earth is straight and linearWRONG!!
6 Aristotle (300 B.C.) Greece (cont.) Aristotle’s ideas about motion were a beginning in scientific thought.
7 Galileo Galilei (1600’s) Italy Discovered moons of JupiterSupported the idea that planets revolve around the SunFamous for ideas on motion…but these were not readily accepted in his time
8 Galileo Galilei (cont.) Galileo’s Ideas on Motion:1. All objects fall at same speed (independent of weight)2. Introduced concept of friction- which slows things down3. Inertia (sluggish or lazy)- tendency of an object to resist a change in its motion
9 Sir Isaac Newton (1700’s) England “Father of Physics”Devised calculusExplained gravity, the universal law of gravitation (apple on head?)Formulated a theory on the nature of lightFormulated the laws of motion
10 Newton’s 1st Law of Motion An object at rest remains at rest…An object in motion maintains its velocity…Net force = 0balanced forces, no acceleration!Unless it experiences an unbalanced force
11 First Law (cont.): INERTIA Newton borrowed the idea from Galileo.The inertia of an object is the tendency of the object to resist a change in motion.The larger the mass of an object, the greater its inertia.
12 Newton’s 1st Law of Motion Apply Newton’s 1st Law of motion to this picture:
13 Newton’s 1st Law of Motion Sports Examples:A moving ball will keep moving forever.Unless slowed by external force of friction (ground, floor) or gravityA soccer ball in grassremains stationary.Until it is kicked (external unbalanced force)