Introduction to Free Fall Impetus Aristotle 384 322

Introduction to Free Fall

§ “Impetus” Aristotle 384 – 322 B. C.

§ “They get tired. ” Aristotle 384 – 322 B. C.

§ “Objects yearn to be reunited with the earth. ” Aristotle 384 – 322 B. C.

Galileo Galilei § 1564 – 1642 § Astronomer § Physicist § Mathematician § Philosopher § Engineer § Many many contributions

§ Inertia § Kinematics § Thermoscope § Law of falling bodies § Improved the telescope § Simple harmonic motion § Parabolic trajectory of projectiles § Publicly supported heliocentric system § Enforced the scientific method by testing hypothesis via experiment

• Does position increase, decrease, or remain constant? • Does velocity increase, decrease, or remain constant? • Does acceleration increase, decrease, or remain constant?

§ Piza

• “Acceleration due to gravity” • Denoted as “g” • Uniform acceleration directed toward the center of the Earth • g = 9. 81 m/s 2 • + or – depending on how you analyze the problem • Letting upward represent the + direction and downward represent the – direction is a bit more conventional

§ Compound body thought experiment

§ Pisa

§ Commander David R. Scott § August 2 nd, 1971 § Hammer vs. feather § Absence of air resistance (in a vacuum) § https: //www. youtube. com/w atch? v=5 C 5_d. OEy. Afk

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§ The speed of sound is 340. 29 m/s. How long did it take Felix to break the sound barrier and how far did he fall? Time elapsed = 34. 9 s Displacement= -5902 m § Note: Use g = 9. 81 m/s 2 “g” actually varies as he falls. .