Chapter 6. Weight and contact forces
Supporting pages (HTML pages with embedded animations) 
Weightlessness vs "weightlessness" 
"Imperial units"  slugs and pounds 
Young's modulus, Hooke's law and material properties
Hooke's law and the limits to linearity. How Young's modulus is related to intermolecular or interatomic forces and energies. 
Simple experiments on coefficients of friction
Using a spring balance and an inclined plane to determine coefficients of friction, and whether they depend on normal force or area of contact. 
Wheels and rolling
Between a rolling wheel and the ground there is no relative motion. We derive equations for the kinematics of rolling. 
Analysing Motion
Using frame grabbing software and spreadsheet software to determine velocity and accleration of an object. 
Car Physics
Acceleration examples: braking with constant force and decelerating with air resistance. Some other problems in car physics 
Background material on gravity
Gravity in context. Newton’s law and the shell theorem, Cavendish’s experiment, planetary motion, satellites, ‘weightlessness’, potential energy, escape velocity, blackholes, the rotation of the earth.

Why g is not parallel to F_{g}_{
}The earth's surface is not an inertial frame, because of the earth's rotation. Consequently, in that frame, Σ F ≠ ma. The approximation that mg = F_{g} is good but not exact. 
Frames of reference for Newton's and Maxwell's laws
 Einstein's relativity 
Revise vectors 
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Weight and contact forces 