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Physics 1 Honors Chapter 4 – Newton’s First Law - Inertia. Section 4.9. The Earth is Moving Again. In the 16 th Century Copernicus put forth the idea the Earth was moving. To get around the sun each year it must be moving at 107,000 km/hr This translates to 30 km/sec
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Physics 1 HonorsChapter 4 – Newton’s First Law - Inertia Section 4.9
The Earth is Moving Again • In the 16th Century Copernicus put forth the idea the Earth was moving. • To get around the sun each year it must be moving at 107,000 km/hr • This translates to 30 km/sec • This information was used to argue against the idea the Earth is moving.
Example • Lets say you have a quarter in your hand. • You drop the quarter. • It falls at your feet. • They reasoned that if the earth was moving at 30 km/sec, and assuming the quarter took 1 second to fall, then: • The quarter should land 30 km from your feet.
Can you refute this argument? • Remember the idea of inertia. • If the Earth is moving at 30 km/sec, so are you and so is the quarter. • Things in motion remain in motion if no force acts upon them. • Therefore the quarter drops at your feet.
Can you refute this argument? • Try standing right next to a wall and jumping. • Did the wall smash into you? • What would happen if you threw a coin into the air from a plane moving at 450 km/hr?
The Earth is Moving Again • We owe this understanding to the work of Aristotle, Galileo and Newton. • Aristotle recognized the unity of all kinds of motion and the effect of friction. • Galileo and Newton both recognized that all moving objects follow the same rules. • These great scientists led us to our present day understanding of motion.