Unit 5: Unbalanced Force (Net Force) Model (UFM)
Learning Targets What you should know when all is said and done
Everything below is written from the Next Generation Science Standards. See this document for evidence statements that will be followed to demonstrate student understanding. By the time you finish all labs, worksheets and related activities, you should be able to: 1. Use Newton's 2nd Law to qualitatively describe the relationship between m and a, F and a, m and F. (e.g., if you double the mass, the acceleration will…) 2. Given a v vs t graph, draw the corresponding a vs t and F vs t graphs. 3. Determine the net force acting on an object by: a. drawing a force diagram for an object given a written description of the forces acting on it. b. resolving forces into x and y components, then finding the vector sum of the forces. c. analysis of the kinematic behavior of the object. 4. Solve quantitative problems involving forces, mass and acceleration using Newton's 2nd Law. a. Having determined the net force (as in #3), and given the mass, find the acceleration. b. Continue to use the kinematical models from unit III to determine the velocity or displacement of the object, once the acceleration is known. Unit 5 Elevator Lab questions Sample video showing your apparent weight in an elevator. Use to help you answer questions on Elevators. The Physics of Elevators A group of physics teachers ride the elevator in the John Hancock Building and in Water Tower Place in downtown Chicago. This one is a little long, but it has an excellent explanation during the video which you will need to be able to explain on the homework and in a free body diagram. http://youtu.be/8JC6dci06Gc 
Notes
U5 Net Force Model Notes (pdf only) Friction Formula and examples (pdf only) Net Force problem examples (pdf only) a nice reading on sliding and static friction and mu from the physicsclassroom Concept Builder help on the Physics Classroom Balanced vs. Unbalanced Forces Newton's 2nd Law calculations Handouts Practice Set packet (pdf only) Unit 5 Moodle Questions (pdf only) Atwood's Machine paradigm lab rubric Unit 5 Study Guide Using Logger Pro to make a graph and to linearize a curved fit Graphing Hints (what to change if a graph is curved) PHeT Simulators use either sim below for N2L lab Forces in 1D Force and Motion Newton's Second Law Simulation Lab (pdf) Review Videos
from Khan Academy Finding the Normal force in an elevator Treating Systems (basics of atwood's machine problems) Two masses hanging from a pulley finding acceleration and tension in the string. Next two are simple, straightforward pulley and "table" atwood problems that are well explained. Both find acceleration and tension. Part 1: Atwood's Machine problems Part 2: Atwood's Machine Problems Practice Set Packet answers (some)
Practice Set 1 part 2 Practice Set 3 Practice Set 4 Practice Set 5 Study Guide #15 Study Guide #14 Study Guide #13 Study Guide 112 just answers, no work A great simulation from PhET on forces, mass, and acceleration titled "Forces and Motion: Basics"
