Machines: Simple Machines Mastery
This section covers the written test portion of the event. The test will be a minimum of 25 minutes and will cover simple machines in static equilibrium.
Event Rules Quick Hit
- Team of 2, device impounded (bound box: 1m x 1m x 0.5m).
- Five machines (B): Levers, Inclined Planes, Wedges, Pulleys (up to 2 double), Wheel & Axle.
- Six machines (C): + Screws. No compounds, dynamics, friction coeffs, or angle of repose.
- Scoring: Exam (45pts) + Time (15pts) + Ratios (30pts) + Chart (10pts—10+ data pts, full range).
Part I: Written Test
- Minimum 25 minutes to complete.
- Answers must be in metric units with appropriate significant figures.
- Questions will be about simple machines in static equilibrium.
Core Concepts
Ideal and actual mechanical advantage:IMA = De / Dr
Efficiency, load, and effort:Eff = (AMA / IMA) * 100%
Potential and kinetic energy:PE = mgh, KE = 1/2mv^2
Coefficient of friction:μ = f / N
States/Nationals Only:Compound machines
Simple Machines
- First class levers
- Second class levers
- Third class levers
- Inclined planes
- Wedges
- Wheel and axle (including gears)
- Pulleys (including rope and pulley systems)
- Screws
Classical Newtonian Mechanics
- Newton’s laws of motion
- Inertia, force, action-reaction
- Position, speed, velocity, acceleration
- Momentum, kinetic and potential energy
- Conservation of energy and momentum
Mathematical Content
- Standard arithmetic operations (including ratios).
- Simple algebra manipulations, including solving one equation for one variable.
- Basic 2D geometry required for resolving forces into component parts (e.g., parallel & perpendicular lines, triangles, basics of vectors).
- Simple trigonometric relations to enable use of trigonometric functions on a calculator.
Homework & Practice
Generator Levels 1-5: Levers, Pulleys, etc. (Download Excel for random probs).
- Start with Level 1: 100% accuracy x3 sheets.
- Build binder: Rules first, then eqs/tables per machine.
- Sample tests: Scioly.org—time yourself!