Concept #1: Static Friction & Equilibrium
Practice: The system below does not move. Find the minimum value that μ,S (between 8 kg block and table) can have.
Practice: A 15 kg block is initially at rest on a horizontal surface. The coefficients of friction between the block and the surface are 0.5 and 0.7. How hard must you push down the block to keep a 300 N force in the +x from moving it?