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Daily Agenda for November 11 th and 12 th. DO NOW: From the front of the classroom, take a Do Now. The Biebs and the Shotput are chilling on my desk. Draw/ describe the forces acting on these guys! Homework due (place in inbox) Newton’s 1 st Law Video Analysis homework
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Daily Agenda for November 11th and 12th DO NOW: From the front of the classroom, take a Do Now. The Biebs and the Shotput are chilling on my desk. Draw/ describe the forces acting on these guys! Homework due (place in inbox) Newton’s 1st Law Video Analysis homework Tonight’s Homework: You’ll get these handouts later in class! Read and Study Chapter 4; answer #1-16 in Early Astronomer Guided Notes. Then, complete the questions on the HW handout: Watch video assignment and complete if you had difficulty over the weekend.
What’s the BIG idea? • Where did Newton’s Law come from? • How did people view motion in ancient times? • What is a force? • Can something be at rest and still have forces acting on it?
Do Now: Force Diagrams What is holding them down? What is keeping the shot put from rolling off the edge? In which directions are these forces acting? **THINK ABOUT THE DEMOs FROM LAST LESSON!** What FORCE caused the shot put to fall? Why did the shot put stop moving? What force to be squished? In which directions are these forces acting? **THINK ABOUT THE DEMOs FROM LAST LESSON!**
Force Diagrams • FORCES are VECTORS which means…
Force Diagrams Magnitude is represented by the Length of the Arrow Small Magnitude: Large Magnitude:
Force Diagrams Direction is represented by the way the arrow is pointed! Force due to Gravity: Force due to Friction: FGravity FFriction
pull push magnitude direction
pull push magnitude direction ∑F… the Greek letter SIGMA. ∑ means “SUM OF” ALL FORCES acting on an object. (Think back to displacement diagrams
Go BACK to your Do Now • Try creating a force diagram for both scenarios! • We will review on board
Force Diagrams FS Ff Fs Ff Ff Fapplied Fg Fg Fg Fg
Force Diagrams FS FS Ff Fg Fknife Or Fapplied Ff Fg Fg
Mechanical Equilibrium ( ME) Static Equilibrium ( SE) Dynamic Equilibrium ( DE) Velocity AND Zero acceleration velocity acceleration
It’s in Mech. Eq! Think back to our Do Now! Weight/gravity Support force They are FORCES but they CANCEL OUT. (SE) Or….something could be MOVING at a constant velocity. Weight and support cancel; push and friction cancel (DE) Mechanical Static Dynamic
CHAPTER 4: Newton’s first law of Motion…inertia **DISCLAIMER** The information you are about to see does not represent the views, beliefs, or scientific facts held to be true by Mr. O’Connor, Mrs. Correia, Mrs. Warren and the scientific community. Please remember that the views expressed are those of really old, REALLY dead scientists who made amazing contributions but weren’t always correct.
Read Aristotle • Answer a through d
WHO? Aristotle(Aριστοτέλης) • WHERE? Greece • WHEN? 4thCentury B.C. • WHAT? Natural motion vs. violent motion; objects belong at rest unless experiencing a push or pull, or returning to rest
Read Copernicus • Answer e
WHO? Copernicus • WHERE? Poland • WHEN? 1473-1543 • WHAT? Earth and other planets move around the sun; his ideas were so controversial that people persecuted him (De Revolutionibus)
Read Galileo and Newton • Answer f
WHO? Galileo Galilei WHERE? Italy WHEN? Late Renaissance (1564-1642) WHAT? Need a force to KEEP an object moving ONLY if there is friction; objects resist change to states of motion (inertia); concerned with HOW not WHY things move
TONIGHT’S HOMEWORK • Read and Study Chapter 4; answer #1-16 in Early Astronomer Guided Notes. • Then, complete the questions on the HW handout: • Watch video assignment and complete if you had difficulty over the weekend. • Remember what the LENGTH and DIRECTION of the arrows mean EXIT SLIPS TURNED IN PLEASE!