Examples: 1. An object with 235.2N of normal force at rest on a flat floor requires a horizontal force of 75 N to set it in motion. Find the coefficient of static friction between the crate and the floor. 2. A 20 N force to the right keeps a 100 N normal force mass at constant velocity on a horizontal surface. What is the coefficient of kinetic friction between the surface and the mass? 3. A 17 N force to the right keeps a 78 N normal force mass at constant velocity on a horizontal surface. What is the coefficient of kinetic friction between the surface and the mass? 4. Mr. White, with 235.2N of normal force at rest on a flat floor requires a horizontal force of 75 N to set it in motion. Find the coefficient of static friction between Mr. White and the floor. 5. A 2000 N force to the right keeps a train with 100 N normal force at constant velocity on a horizontal surface. What is the coefficient of kinetic friction between the surface and the train