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HAPPY WEDNESDAY! •Please get your folders. •If you finished your graph and conclusions for Part 2, have them out. •Copy down tonight’s homework. Today, we will: Talk about Newton’s 1st Law of Motion Warm-up Try to do the demonstrated action. Write about what you think is going on. Use the words “force” and “motion” in your answer. Sir Isaac Newton (1643-1727) was an English scientist and mathematician. He was famous for his discovery of the law of gravity, and he also discovered the three laws of motion. And calculus… Newton’s First Law An object at rest stays at rest and an object in motion stays in motion at constant velocity unless acted upon by an unbalanced force. WHAT DOES THIS MEAN??? Basically, an object will keep doing what it is already doing unless acted on by an unbalanced force. If the object was sitting still, it will remain stationary. If it was moving, it will keep moving at the same speed in the same direction. It takes force to change the motion of an object. How does Newton’s First Law apply to this movie? Play Movie Newton’s 1st Law is also called THE LAW OF INERTIA Inertia is a physical property of matter. It describes an object’s resistance to changes in its motion. Newton’s 1st Law states that all objects have inertia. The more mass an object has, the more inertia it has (and the harder it is to change its motion). SOME REAL LIFE EXAMPLES: A powerful locomotive begins to pull a long line of boxcars that were sitting at rest. Since the boxcars are so massive, they have a great deal of inertia and it takes a large force to change their motion. Once they are moving, it takes a large force to stop them. On your way to school, a bug flies into your windshield. Since the bug is so small, it has very little inertia and exerts a very small force on your car (so small that you don’t even feel it). Example of an object having large inertia: USS Nimitz: Length: 332m (1092 feet) Beam (width): 40.8m (134 feet) Mass: 86,183,000 kg (190 million pounds) Speed: 15 meters/second (34 mph) So if the carrier is moving at 34 mph and shuts its engines down, how far will it drift? A hundred feet? A thousand feet? A mile? In turns out that the stopping distance (in a smooth sea) would be about 32 km (20 miles), if no active measures are taken to stop the forward motion of the carrier (such as reversing the engines). I don’t have a video of the USS Nimitz, but check this out! ARE YOU READY FOR SOME MAGIC??? Attempt by the Mythbusters, in slow motion… Yeah, that was fake… Could you tell how??? Before you leave… What is inertia? The glass that you brought up to your bedroom is sitting on the floor next to your bed. What does Newton’s 1st Law say about that glass? You hit a fly ball toward left field. What does Newton’s 1st Law say about that ball? Huh??? Was Newton crazy???