Do Now: 1. Walk in silently. Reminders: Kelly is out Mon & Tues! Project description will be posted on my website (hard copies available on Monday). Fri 11/2 we will do a showcase/peer evaluation of the projects. 2. Grab a calculator and any papers for today. 3. Lab out on your desk, ready to discuss. 4. You will be taking your own notes today! Notebook paper out! Created by M. Kelly OBJECTS IN MOTION STAY IN MOTION!
Based on the picture, what do you think we are talking about today?
By the end of today, IWBAT - Understand why objects move - Define balanced and unbalanced forces - Understand Newton s 1 st and 2 nd Law - Understand inertia Why it matters in LIFE: Part of being a functional human being is being able to understand what s happening in the world around you! Why it matters in THIS CLASS: Our Goal = 80% Mastering today s lesson (focused participation, asking questions, etc) is the first brick that will help us reach our goal for this unit, and eventually for the year
TEKS: 4(D) calculate the effect of forces on objects, including the law of inertia, the relationship between force and acceleration, and the nature of force pairs between objects; By the end of today, IWBAT -understand why objects move -calculate force in simple situations U3-2 Newton s 2 nd Law: Balanced vs. Unbalanced Forces
A force is a push or a pull
WHAT HAPPENS WHEN YOU PUSH OR PULL SOMETHING? IT SPEEDS UP!
FORCE, F (units - Newtons, N) A push or a pull on an object that changes its velocity. acceleration speed up, slow down, or change direction
HOW MANY FORCES ACT ON THE BASEBALL?
1. PA R T N E R U P. 2. G R A B 1 C H R O M E B O O K P E R G R O U P. 3. C O M P L E T E T H E E N T I R E L A B A N S W E R I N G I N C O M P L E T E S E N T E N C E S.
NEWTON S LAWS NOTES 1st Objects in motion stay in motion and objects at rest stay at rest unless acted upon by an unbalanced force. 2nd F = m* a 3rd For every action there is an equal and opposite reaction.
NEWTON S 2 ND LAW The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. ΣF = m a F = sum of the forces (N) m = mass (kg) a = acceleration (m/s 2 )
MASS, m (units - kilograms, kg) The measure of matter in an object. The mass of an object is the same no matter where you are. It s an object s weight that changes.
BALANCED FORCES Forces are balanced when the F = 0 NO ACCELERATION Object is said to be in equilibrium ( F = 0, a = 0) Examples Car driving at a constant velocity You sitting in your chair Arm wrestling (when it s tied)
UNBALANCED FORCES Forces are unbalanced when F 0 Object is speeding up, slowing down, or changing directions Examples Car pulling out of the driveway You getting up out of your chair Arm wrestling (when someone is winning)
NEWTON S FIRST LAW! AN OBJECT IN MOTION STAYS IN MOTION, AND AN OBJECT AT REST STAYS AT REST UNLESS ACTED UPON BY AN UNBALANCED FORCE.
During video: 1. Listen carefully 2. Take quick notes *focus on inertia https://www.youtube.com/watch?v=jgo_zd Wmkvk
INERTIA The tendency of an object to resist changes in motion. An object wants to keep doing what it s already doing.
HOW DOES MASS EFFECT INERTIA? The greater the mass of an object, the greater the net force required to get it moving or to change its motion Therefore, the greater the mass, the greater the inertia Which has the most inertia?
LIGHTNING PRACTICE!
A BALL ROLLING DOWN A HILL. BALANCED OR UNBALANCED?
A BALL ROLLING WITH A CONSTANT VELOCITY ACROSS A TABLE. BALANCED OR UNBALANCED?
THE SUM OF THE FORCES IS ZERO. BALANCED OR UNBALANCED?
A MAN PUSHING A BOX ACROSS A FLOOR WITH NO ACCELERATION. BALANCED OR UNBALANCED?
AN APPLE FALLING TO THE GROUND. BALANCED OR UNBALANCED?
A SPACESHIP FLOATING THROUGH SPACE WITH IT S ENGINE TURNED OFF. BALANCED OR UNBALANCED?
THE OBJECT IS IN EQUILIBRIUM. BALANCED OR UNBALANCED?
TWO METEORS COLLIDE IN SPACE AND ARE REDIRECTED. BALANCED OR UNBALANCED?
THE SUM OF THE FORCES IS NOT ZERO. BALANCED OR UNBALANCED?
JUMPING. BALANCED OR UNBALANCED?
A CAR COMING TO A STOP AT A STOPLIGHT. BALANCED OR UNBALANCED?
A CHAIR OR A COUCH. WHICH HAS MORE INERTIA?
TUG OF WAR (TIED). BALANCED OR UNBALANCED?
A WHALE OR A FISH. WHICH HAS MORE INERTIA?
THE MOON IN ORBIT AROUND THE EARTH. BALANCED OR UNBALANCED?
TUG OF WAR (ONE TEAM IS WINNING). BALANCED OR UNBALANCED?
A TENNIS RACQUET HITTING A BALL. BALANCED OR UNBALANCED?
A TEXTBOOK SITTING ON A DESK. BALANCED OR UNBALANCED?
AN EMPTY BOWL OR A BOWL FULL OF CEREAL. WHICH HAS MORE INERTIA?
Which body is in equilibrium? a) a satellite moving around Earth in a circular orbit b) a cart rolling down a frictionless incline c) an apple falling freely toward the surface of Earth d) a block sliding at constant velocity across a tabletop
EXIT TICKET 1. 3. 2. Summarize Newton s 1 st Law and tell me it s other name!