Force and Motion

1/27 Weekly Highlander Sheet Objective: Students will brainstorm about “force” and create a working definition for force and investigate evidence of various types of forces. Responsibilities: Check last quarters grade, make sure it is up to date with all but Extra Credit

Warm Up: FORCE We have all heard the word “force”- we have even used it… but can you define it? Write out your own definition of force. What would a scientific definition of force sound like? Are there any forces acting on you right now?

Nature of Forces Forces are a push or pull Forces can be added Forces have direction as well as size Unbalanced forces result in a change in motion Balanced forces result in no change in motion

Evidence of Force Indicate what force is present Describe the force. For each item in the basket: Indicate what force is present Describe the force. Identify what EVIDENCE you have that there are forces acting. What should I know now? … Unbalanced forces cause change in motion. Forces are a push or a pull.

Types of forces Magnetic (non-contact) Gravity (non-contact) Elastic Spring Friction (contact) Electrostatic (non-contact) Cetripedal

Types of forces Magnetic (non-contact) Gravity (non-contact) Elastic Spring Friction (contact) Electrostatic (non-contact) Cetripedal

WHOT Q Types of forces

Force and Motion

1/28 Weekly Highlander Sheet Objective: Use force diagrams to simulate 2 forces acting upon each other. Responsibilities: Take amazing notes for all force diagram questions.

Please pick up your stuff and head to the back of the room

Warm Up:

The additive force acting on an object Net force defined… The additive force acting on an object

Individual practice… write these in your journal for notes *Note* Take care to notice the size of the arrows.

Let’s practice… Elbow partners take good notes

Acceleration Defined… A change in velocity's speed or direction

http://www.youtube.com/watch?v=dQmYBF_Sd8I

Lets try a problem…

WHOT Q: What is evidence that there are unbalanced forces acting on an object?

Force and Motion

Warm Up: Newton’s second law problem

Whiteboard and Teach Diagnoser: Identifying Forces Diagnoser: Effects of Pushes and Pulls Set 1 Decide who will be the initial SCRIBE, take turns Everyone must say something during the presentation portion Complete the following as a team: Read the question Reread the question Rule out the incorrect answers by determining what the outcome of would be Finally write a statement and DRAW a picture that shows the concepts on the correct answer.

Example Gravity pulls with equal down force as the table pushes with up force Resulting in NO NET FORCE- so the book stays put After a lecture on forces in science class, Frank was thinking about the forces acting on a box at rest on his desk. Which statement do you think best represents the forces acting on the box? (a) No forces act on the box at rest. (b) The force of gravity is the only force acting on the box. (c) Earth pulls down and the table pushes up equally on the box. (d) The downward pull of gravity is larger than the upward push of the desk.

Exit ticket: Please put a proper heading on your (recycled) paper to turn in. Use complete sentences when writing your response. You are so excited and Ms. Lin is very scared- because you just got your divers license! You are sitting in the drive-way waiting for your friends to come over and see the awesome picture on your new ID. While you sit you start dreaming about cruising along in your ride… but then physics creeps in your head and you begin to wonder…How does the car move forward? Here are your ideas… The energy in the battery pushes the car. The motion forward indicates the car has a force of motion. Since the tires are moving, they push the car. The friction of the floor on the tires pushes the car forward. I need to take more physics and auto shop. Thank you for NOT folding the paper and handing it to Ms. Lin thoughtfully as you exit.

Force and Motion

Dimensional Analysis How much force do I exert on the floor- and inevitably the Earth? weigh 124 lbs

Ben Tooclose is being chased through the woods by a bull moose which he was attempting to photograph. The enormous mass of the bull moose is extremely intimidating. Yet, if Ben makes a zigzag pattern through the woods, he swill be able to use the large mass of the moose to his own advantage. Explain this in terms of inertia and Newton’s first law of motion.

You are traveling in space and are working outside of your spaceship making repairs. You accidentally throw your wrench. What happens to the wrench? Why is this different from what would happen on earth?

You have just been to the grocery store and have several paper bags full of groceries standing in the back of your van. You have to make a sudden stop. What happens to the groceries and why?

Warm Up --interpretation of velocity : time graph Describe a story that would be represented by this motion Force diagrams (see attached presentation pages) Read first section of Hewitt reading out loud Concept of net force ID forces on a book sitting on a table Discuss normal force Use pillow and foam as props to show visible upward forces Forces are measured in Newton’s-demo spring scale ID forces on hanging object Use bungees and string as props to show visible upward forces Newton’s 2nd Law Unbalanced forces cause change in motion Diagrams of balanced and unbalanced forces and resulting motion If time, weight vs mass Give examples for homework from Hewitt on equilibrium