Final Exam Review – Kinematics, Kinetics & Collision Concepts
Exam Structure and Stakes
Format & weighting
Only 5 multiple-choice questions; all remaining questions are open-ended.
Expect heavy typing: you must show every step of your work to receive full credit.
The final counts for 40\% of the total course grade.
A poor score can jeopardize passing the course and may require a retake.
Grading mindset
Instructor will look for orderly work, clear reasoning, and correct units.
Partial credit is possible, but only if intermediate steps are visible.
Kinematics (Week 1 Review)
Core idea: relationships among time, distance, velocity, and acceleration.
Key equations (must know, derive, and apply):
Average velocity: v = \frac{d}{t}
Average (constant) acceleration: a = \frac{vf - vi}{t}
Unit-conversion warning
Problems may request an answer in miles per hour (mph) while giving time in minutes.
Procedure: convert minutes to hours before substitution.
t{\text{hours}} = \frac{t{\text{minutes}}}{60}
Omitting this step leads to an incorrect numerical answer and loss of credit.
What to show in solutions
Known values (with units).
Unit conversion step.
Substitution into the equation.
Final answer boxed and in requested units.
Kinetics (Forces & Motion)
Big picture: Why things move—forces and interactions.
Newton’s Three Laws (must cite & apply to one coherent scenario):
Law of Inertia – An object at rest or moving at constant velocity remains so until acted on by an external net force.
Law of Acceleration – The acceleration of an object is proportional to the net force and inversely proportional to its mass ( F_{\text{net}} = m a ).
Law of Action–Reaction – For every action there is an equal and opposite reaction (force pairs act on different bodies).
Required exam task
Compose or reuse a physical scenario (may reuse one from the earlier study guide) that explicitly shows:
Initial rest or constant-velocity state.
Introduction of an unbalanced force → change in motion (acceleration).
Clear identification of the action–reaction pair.
e.g.
A skateboarder pushing off the ground.
A snowball hitting a wall.
Use correct terminology and link each part of the scenario to the relevant law.
Collisions: Elastic vs. Inelastic
Elastic Collision
Both momentum and kinetic energy are conserved.
Typical example: two ideal billiard balls striking and separating without deformation.
Inelastic Collision
Momentum is conserved, but kinetic energy is not (some converted to heat, sound, deformation).
Perfectly inelastic subtype: objects stick together post-impact.
Example: car crash with crumpling metal.
What to demonstrate on the exam
Define each collision type.
Explicitly state which physical quantities remain constant.
Provide or analyze a concrete example for each.
Practical & Ethical Connections
Unit discipline carries over to engineering, aviation, medicine—wrong units can be catastrophic (e.g.
Mars Climate Orbiter loss due to metric–imperial mix-up).
Ethical implication: engineers and scientists have a duty to communicate calculations transparently—mirrors the “show your work” rule.
Final Preparation Checklist
Memorize and practice manipulating the two kinematics formulas.
Drill unit conversions (minutes↔hours, meters↔kilometers, ft↔miles).
Build a robust scenario illustrating Newton’s laws; rehearse writing it quickly.
Know the conservation properties of elastic vs. inelastic collisions.
Practice open-ended problems—type solutions as you will on the exam (speed matters).
Double-check that every numeric answer carries the correct unit.
Aim for clarity: label steps, underline final answers, and reference laws explicitly.
Good luck—master these points, show every step, and the 40 % weight will work in your favor!