Physics 3 – Aug 30, 2016 Do Now: P3 Challenge – (on slips of paper) A 3.5 kg block on a level surface is being pulled by a horizontal 45 N force. What is the acceleration of the block if the dynamic coefficient of friction between the surface and the block is 0.15.

Objectives/Agenda Objective: Forces Agenda: Review IB information about 2.2, 2.3, 2.4 Review list of specific concepts and skills for Unit 3-5 Self ratings to determine which to clarify or practice Practice the needed concepts and skills for Unit 3 Assignment: Prepare for Unit 3-5 Mastery Quizzes Next week

Skills and Concepts: Where are you? Refer to the IB Objectives List Assess where you are with each objective: 1 – Got it, know about it, know how to do problems, could write my own problems 2 – Pretty sure I remember, know where to find formula on data packet, could use a refresher 3 – Need to review, never did quite get that, don’t remember 4 – Greek, never did it,

Review as needed Teacher reteach mini- lesson Classmate clarifications Teacher created problems to solve (pop quiz) to verify proficiency (boost grade) Student created problems to cross challenge Selection of textbook problems for practice Revisit last year’s materials Record summary statements or recommendations for these kinds of problems Create a concept map Other ideas?

Typical Second Law Problem Solving 1) Draw the system. Label with masses and Forces and any other data. 2) Choose the body of interest (to be treated as a point mass) 3) Draw the Free Body Diagram, including all forces acting on the body of interest. Include the direction for each. 4) Resolve all forces at an angle into their x and y components. 5) Write the expression for the net force in each dimension (Right – left, Up – down) 6) Write the second law equation for each dimension Fnet,x = max Fnety = may 7) (Opt) Connect to kinematics.

Topics Reviewed Aug 30 Newton’s Second Law Problem set out of Giancoli Physics including Mass of fish on a fishing line when snaps… Man on scale in an elevator (1st and 3rd law implications) Man pushing a lawn mower at both const. speed and accelerating. Three blocks on a frictionless surface, looking at multiple FBDs Atwood’s machine (two masses connected over a pulley) Static friction present on a jammed drawer Bar of soap sliding down an incline

Today’s Assignment Continue reviewing 2.2, 2.3, 2.4 Prepare for Unit 3-5 Mastery Quizzes Next week Mastery quizzes are worth 10 points and will be two multiple choice questions with 8 points of problems. (Usually one or two problems). IB materials will be integrated as much as possible. May retake mastery quizzes as needed to reach 8/10 proficiency level.