Unit 2 - Forces
Points
0 = Not Yet
Grading Scale
270-300 = A
60 = Basic
80 = Proficient
100 = Mastery
Standard
2.1
240-269 = B
210-339 = C
180-209 = D
0-179 = F
Not Yet
Does not understand the concept of inertia.
Basic
Confuses the terms momentum and inertia. Momentum is dependant on velocity and mass while inertia depends only on mass.
Can solve basic problems involving F, m, and a. Struggles in determining net forces and friction. Unable to break force vectors into vertical and horizontal components.
2.2
2.3
Is unaware of the relationship between force, mass, and acceleration.
Does not realize that all forces come in pairs.
Standards on the back side.
Knows that forces come in pairs, but is unable to identify reaction forces. mrwilterdink.pbworks.com
Proficient
Is able to define inertia and provide examples of inertia. If given two objects, can determine which one has the most inertia.
Mastery
Realizes that inertia only depends on an object's mass, not its velocity. Can apply the concept of inertia to everyday situations.
Can solve most problems involving F, m, a, and friction.
Able to break force vectors into vertical and horizontal components. Has difficulty distinguishing between net force, normal force, and friction force.
Able to correctly identify actionreaction pairs. Has difficulty applying Newton's 3rd Law to real world situations.
Able to distinguish between net force, normal force, and friction force when setting up and solving friction problems.
Has difficulty applying Newton's
3rd Law to real world situations.
Able to identify which objects forces are acting on in order to determine the net force.

2.1 Understands that inertia is a resistance to a change in motion and that objects with more mass have more inertia than objects with less mass (Newton's 1st Law).
2.2 Understands that acceleration is created by a net force on an object. The greater the net force and the lower the mass, the more an object will accelerate (Newton's 2nd Law).
Realizes that friction is a force that always acts in the opposite direction as velocity causing objects to slow down. Is able to solve problems involving net force, mass, acceleration, and friction.
2.3 Understands that all forces come in pairs. The paired forces are always equal in magnitude, but opposite in direction (Newton's 3rd Law).
Key Vocabulary: coefficient of friction - experimentally determined value that is dependant on the two surfaces in contact with one another; all values are positive; values closest to zero represent the least amount of friction. concurrent forces - multiple forces acting on the same object at the same time. inertia - an object's resistance to a change in motion. net force - the vector sum of all the forces acting on an object. normal force - the force perpendicular to a boundary between two surfaces
Useful Equations:
F net
= ma
W = mg
F f
= F
N
μ
F net
= net force (in N) m = mass (in kg) a = acceleration (in m/s 2 )
W = weight (in N)
F f
= friction force (in N) m = mass (in kg) g = gravitational acceleration (9.80 m/s 2 on Earth)
F
N
= normal force (in N) μ = coefficient of friction