Introduction:     Ch4intro.pptCh4 Equilibria.ppt   OR  Ch4intro.mht

Universal Gravitational Force: universal gravitation.mht

Dealing with varying forces:   varying force2.pptvector add.ppt

Friction:  Slip Slidin’ Away.pptx    OR  Slip Slidin’ Away.mht

Systems in Equilibrium:   Ch4 Equilibria.pptvarying force2.ppt   OR   Ch4 Equilibria.mht