PHY201 Mechanics Topic Checklist

Have you…? Answered all (A and M) questions from the homework booklet? Marked your answers? Corrected your answers? Shown correct working? (Formula, Substitution, Units, etc.) Memorised all of the important stuff?

Exam Techniques: UNITS!!! (grams, cm, km, minutes, etc.) Attempt ALL questions (10As better than 3Es) Manage your time (skip questions if you need) Read questions to the end, carefully Check your calculator (deg or rad?) Premature Rounding & Significant Figures UNITS!!! (grams, cm, km, minutes, etc.)

Kinematics Practice, practice, practice (Homework booklet & Textbook Activity 7C) “KUFSS” – follow the steps and SHOW WORKING

Vectors: Vector diagrams – LABEL your vectors Arrows!!!! (and a double arrow for the resultant vector) Calculate the angle (direction) if the questions asks for direction Remember: Δv = vf – vi

Projectile Motion: There is only ONE FORCE acting on the object, which is the downward weight force (assume friction is negligible) Horizontal velocity remains constant Two sections: “Vertical” and “Horizontal” Split the initial diagonal velocity (into VV & VH) “Total Flight Time” – double the time!! Final Velocity = Initial Velocity, into the ground

Forces: Draw a labelled diagram (PLEASE) Newton’s Laws – memorise them and UNDERSTAND them “Are forces balanced or unbalanced?” Force vs. Net Force (Fnet = ma) Draw a labelled diagram (PLEASE)

EQUILIBRIUM Torque & Equilibrium: Don’t forget Step #1 – label all forces and distances “Choose a pivot” – the pivot tells you the distances Two sections: “Anticlockwise torques” and “Clockwise torques”

Momentum and Impulse: Draw a labelled diagram (PLEASE) CONSERVATION OF MOMENTUM (Σpi = Σpf) Momentum is a vector quantity (direction, direction, direction) Two sections: “before” and “after” Draw a labelled diagram (PLEASE) ΔpA = - ΔpB

Momentum and Impulse (contd.): Δp = “impulse” (= change in momentum) Δp = pf – pi Δp = FΔt Examples: Falling vase, Air bag, Crumple zone, etc. (have a look at these again) “Elastic collision or Inelastic collision?” – Is the total kinetic energy same before and after?

Circular Motion: Fc , ac , v – DIRECTIONS Period or Frequency? (know the definitions, think carefully) Circumference = 2πr Changing direction → Changing velocity → Acceleration → Unbalanced Force (called centripetal force, towards centre)

Elastic Energy & Hooke’s Law: Conservation of Energy Principle – MEMORISE THIS and USE IT “Because some energy is transformed into heat, because of friction between…” Hooke’s Law: F = kx (don’t worry about the negative sign) x = length of STRETCH (or compression), NOT the actual length

Work & Power: ENERGY TRANSFORMATION (energy → energy → energy → …) Work = amount of energy transformed Power = how fast work is being done (work done per second) W = Fd (beware of diagonal forces!) UNITS