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
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.
Student Learning Goals (A nice concise study guide)
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.
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
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)
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, straight-forward 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 1-12 just answers, no work
A great simulation from PhET on forces, mass, and acceleration titled "Forces and Motion: Basics"