Unit 4: Balanced Force Model (BFM)
What you should know when all is said and done
By the time you finish all labs, worksheets and related activities, you should be able to:
1. Describe and give examples of Newton's 1st Law.
Newton's 1st Law: An object at rest or moving at constant velocity continues its current motion unless acted upon by an outside agent (force).
2. Given a diagram or a written description of the forces acting on an object.:
a. draw a force diagram for the object
b. resolve the forces into x and y components, then find the vector sum of the forces.
c. state whether the velocity of the object is constant or changing.
3. Given a diagram or description of an object in equilibrium, including the forces acting on the object, determine the magnitude and direction of the "missing" force required to keep the object from accelerating.
4. State Newton's 3rd Law; apply it in situations in which you are trying to determine all the forces acting on an object.
All forces come in pairs; paired forces are equal in magnitude, opposite in direction and act on separate bodies. FAB = -FBA
Handouts and Notes
Unit 4 Moodle questions (PV students only)
Unit 4 Minds on Physics record page for Newton's Laws (PV students only)
Complete NL 1, 2, 5, and 12
Unit 4 Practice Set Packet (PV students only)
Unit 4 power point (pdf version)
Why Does the Earth Spin?- a great short video from Veritasium about inertia
Practice Set packet- SOME answers
PS1- page 1 page 2 page 3
PS2- page 2
PS3- page 1 page 2 page 3
PS5- page 1 page 2 page 3
Helpful websites/notes from a great Physics Teacher- Kelly O'Shea
1) Common Types of Forces (the first notes we took)
2) Building the Balanced Force Model- great overview on drawing free body diagrams
3) Gravitational Force Lab (another excellent description of our lab on Fg vs mass)
Vector Addition Diagrams
4) Notes on Vector Addition diagrams
Print your own graph paper or go to this website
1) Trig Reading (Start here!! This contains everything you will need to do with trig for this class)
2) Trig Table
3) Trig Practice problems
1) Newton's 3rd Law. Includes several basic examples and how to draw force diagrams (free body diagrams)
2) Teacher workshop on Newton's Third Law D. Desbian
3) Free Body Diagrams (Force Diagrams). How to draw them. Does include unbalanced forces (we'll cover these in Unit 5), but this video is a good basic overview. Does not include quantitative calculations.
4) Force Diagram w/ components. A slightly different explanation of components and finding the magnitude of the component. Stop watching after the first 8 or 9 minutes (we won't do the rest of it just yet)
Unit 4 Review and Hints
1) Unit 4 Study Guide (pdf) (doc) (some answers)
2) The Physics Classroom Review Problems
Do these Answers here
To view the next two files you must have Logger Pro installed on your computer.
1) Logger Pro file on tapping an Air Puck (w/ motion maps)
2) Logger Pro file on blowing air puck w/ constant force