Important terms:

• Dry Friction
• Normal and Tangential
• Static Friction
• Kinetic Friction
• Normal Force
• Impending Motion
• Coefficients of Friction
• Angle of Friction

Link to glossary

• Normal and Tangential Axes (4.1, pp.61-62, Figures 4.1 and 4.2)
• Laws of Dry Friction (4.1, pp.62-66)
• Forces of Friction (4.1, p.62, Figure 4.3)
• Empirical Determining Coefficients of Friction (4.2, pp.67-70, Figures 4.8 and 4.9)