Test #3:  Newton's Laws in 1-D

Format:

• 8-10 multiple choice
• 3-5 short answer
• 5-7 problems.  Some with 2-3 parts to provide framework, "but no extended problems."

Expect questions and problems similar in structure or concept to questions, problems, and concepts in the following documents...

•  Filled-In Notes on Newton's 1st and 2nd Laws
• Practice with forces in 1 dimension Answers/solutions
• Friction notes (filled-in)
• Filled-in Drag and Terminal Velocity Notes
• Filled-in 3rd law notes -- If you're in 7/8, we didn't finish the tension and pulley part of this, but we covered the topic in the course of working problems.  Still, you might want to look at that page.
• Multibody Drill A  Multibody Drill A Solutions -- Stapleton  Video for problem 2  Video for problem 6
• Practice Test: Newton's Laws in 1-D (all except problem #6)   Answers but not solutions  Problem Solutions
•  Some more practice questions/ problems. Solutions

Concepts:

1. Be able to draw a diagram showing all of the individual external forces and net force acting on an object or system.  Be able to do this for a system as a whole, and also for parts of that system.
   1. Objects experiencing 1 non-canceling external force
   2. Objects experiencing 2 or more non-canceling external forces (e.g. gravity, tension, a push or pull...)
2. Identify action and reaction force pairs
3. Free-fall vs terminal velocity
4. Friction, µ_s vs. µ_k
5. Terminal velocity and skydiving  -- draw a free-body diagram with correct relative forces and net forces for any point during the fall.
6. Forces acting on an object during a series changes in motions.
7. Two ways to determine net force:  1)  ma    2)  vector sum of forces
8. Relationship between inertia, mass, and weight
9. Difference between F and F_net
10. Tension
11. Motion when F_net = 0
12. Bathroom scale reading versus weight
13. Relationship between mass and acceleration when force is kept constant

Some types of problems:

1. Draw a diagram showing net force and individual forces.  Solve for a missing individual force or net force.

2. Calculate weight on another planet

3. Solve for a variable in  F_fr = µF_N

4. Solve for a variable in F_net=ma (one non-canceling force)

5. F_net=ma with two or more non-canceling forces (or canceling forces)

   1. Objects on a string (or cable)

      1. pulled up

      2. suspended

      3. pulled down

      4. lowered down

   2. Objects on a bathroom scale

      1. pushed up

      2. lowered down

      3. suspended

6. Incorporate kinematics formulas into any of the above problems.  Solve for kinematics variables, force, mass, or coefficient of friction.

7. Accelerations and tensions in a system of blocks connected by strings.  Some blocks may be hanging, and some may be sitting on a surface with or without friction.

8. Accelerations and forces in a system of blocks connected by contact forces.