Presentation on theme: "Do now 4/10 Review: Write a hypothesis for the following problem: I want to know if using natural toothpaste makes my teeth white than using regular toothpaste."— Presentation transcript:
Do now 4/10 Review: Write a hypothesis for the following problem: I want to know if using natural toothpaste makes my teeth white than using regular toothpaste.
Exam make-ups Tomorrow after school in my room Grades close Friday
Science Fair Report draft is due written neatly by Friday April 13, 2012 Final draft due typed with display board no later than April 18th, 2012 Science Fair is April 19-20th
Plan for this week: Tuesday: Science Fair Wednesday: Newton’s 1 st Law Thursday: Newton’s 2 nd Law Friday- Science Fair draft due- work on display boards in class
DO NOW 4/11 Anne drops a plastic fork and a metal fork of the same size and shape at the same time. Which one do you think will hit the ground first? Why? ANSWER IN TAG OR RECEIVE ZERO POINTS
Reminders Science fair report draft due Friday Grades close Friday Make up exam today at 3:45
Agenda Do now 3 min Notes – 5 min Practice notes – 2 min Activities – 10 min Ip – 5 min Closing 2 min
Topic: Newton’s 1 st Law (Inertia) 4 slides of notes Write Questions as you go, I will give examples
1 ST LAW OF MOTION (LAW OF INERTIA) Newton’s 1st Law says that an object at rest will remain at rest and an object in motion will remain in motion unless an unbalanced force acts upon it.
Questions Notes What is Newton’s 1 st Law and how is it related to inertia? Newton’s 1st Law says that an object at rest will remain at rest and an object in motion will remain in motion unless an unbalanced force acts upon it.
1 ST LAW Also known as the LAW OF INERTIA! Inertia: The resistance of any object to a change in its motion, whether its moving or not. More Mass = More Inertia Less Mass = Less Inertia These pumpkins will not move unless acted on by an unbalanced force.
Questions Notes What is inertia and how is it related to mass? Inertia: The resistance of any object to a change in its motion, whether its moving or not. More Mass = More Inertia Less Mass = Less Inertia
1 ST LAW examples Golf Ball - once airborne it would never stop! unless acted on by an unbalanced force (gravity and air – fluid friction)
Questions Notes Why does a golf ball hit into the air keep going if it has inertia? Once a golfball is n the air it would never stop unless another force acts on it- like gravity
1 ST LAW Unless acted upon by an unbalanced force, this golf ball would sit on the tee forever.
Questions Notes Unless acted upon by an unbalanced force, this golf ball would sit on the tee forever.
2 minutes practice notes
Newton’s 1 st Law You are driving in a car with no seat belt on. You see a family of ducks and slam on your brakes to avoid hitting them. Since you are not wearing your seat belt, you fly out of the car (remain in motion) until you hit the ground (an unbalanced force). AHH! Ouch In motion…At rest…
Answer the following question with a partner at your table Be prepared to share when called on. (LIBRARY VOICES, 1 minute). You are being chased through the wilderness by a gigantic elephant. The elephant’s mass would be threatening, however, if you zigzagged, the elephant’s mass would work to your advantage. Why is that? Explain using the word “inertia”.
Newton’s Law Activity You have 7 minutes, at your table, in library voices. Complete the activity at your table and answer the questions in COMPLETE SENTENCES
1.Newton’s first law is working because it shows how an object can be affected by something else. That shows the part “an object in motion stays in motion until acted on by an apposing force.” The force of the washers pushing the other washers in the greater force 2. in this quick experiment when you hit he washers against washers, they move. In newton's laws it says it wont move unless an object acts upon 1`it in this case 3. The first stack of washers that is being flicked is a balanced force and the second stationary one is balanced. When one stack is flicked by your finger the applied force then makes it unbalanced and when the second stack is hit by the first one it also becomes unbalanced until gravity stops it. 4.Our objects were at rest and remained at rest which relate to newton b/c the object will motion rest unless any type of force is acted on it
the objects are moved determined by the force applied If something is at rest, it stays at rest/ in motion stays at motion The amount of washers flicked is the amt that get replaced Objects are moved determined by force applied
Answer the following question with a partner at your table Be prepared to share when called on. (LIBRARY VOICES, 1 minute). If you slide a book across a table, it slides to a rest position. Use Newton’s 1 st Law to explain Why this happens
The book comes to a rest because of the presence of a force - that force being the force of friction - which brings the book to a rest position.
In the absence of a force of friction, the book would continue in motion with the same speed and direction - forever! (Or at least to the end of the table top.)
INDEPENDENT PRACTICE SILENT AND ALONE OR RECEIVE A DETENTION YOUR WORK MUST BE INITIALED BY ME BEFORE CLASS ENDS Read pages until newton’s second law and answer questions 15 and 16 on page 85
Closing: Explain how Newton’s 1 st Law is demonstrated in the graphic below.
Do now 4/12 Use Newton’s First Law to explain the “magic trick” in this video. USE YOUR NOTES
“An object at rest remains at rest, and an object in motion continues in motion with constant velocity (that is, constant speed in a straight line) unless the object experiences a net external force.” This is also known as the Law of Inertia.
Agenda Do now (5 min) Notes (2 min) Whole Class Practice (15 min) Practice in groups (10 min) IP (10 min) Closing (5 min)
Topic: Newton’s 2 nd Law (F=MA)
* Or, simply put F=ma. * Force is equal to mass times acceleration * An object will accelerate in the direction of any net force applied to it. * The greater the force, the greater the acceleration. * The greater the mass, the slower the acceleration. * Or, simply put F=ma.
Things move faster and farther when they are pushed harder. Things move in the direction pushed unless another force changes the direction
Something with less mass needs less force to move!
Smart car- Mass: 730 kg Hummer- Mass: 2200 kg How much force does it take to accelerate a hummer and a smart car 10m/s/s? Which requires less force?
Smart car- Mass: 730 kg Hummer- Mass: 2200 kg If you don’t have a lot of money for gas (force) what car is the best option?
A 100-kg crate, sliding on the floor, is brought to a stop by a 25-N force. What is the deceleration of the crate?