Ch 2. Particle Force and Acceleration dy Multimedia Engineering Dynamics Rect.Coord. Normal/Tang. Coord. PolarCoord. Orbital Mechanics Computational Mechanics
 Chapter - Particle - 1. General Motion 2. Force & Accel. 3. Energy 4. Momentum - Rigid Body - 5. General Motion 6. Force & Accel. 7. Energy 8. Momentum 9. 3-D Motion 10. Vibrations Appendix Basic Math Units Basic Equations Sections Search eBooks Dynamics Statics Mechanics Fluids Thermodynamics Math Author(s): Kurt Gramoll ©Kurt Gramoll

 DYNAMICS - CASE STUDY Introduction Problem Diagram At the ACME factory, crates containing precious goods are carried through the plant on conveyor belts. When a conveyor belt stops, the boxes must not slide or the goods may be damaged. What is known: The conveyor belts move at a constant speed of 10 ft/s. The crates first travel on a horizontal belt, then down a belt with a 15° decline. The static, μs, and kinetic (dynamic), μk, coefficient of friction, μs, between the belt and the crates are = 0.5 and 0.3, respectively. Box Stops Click to view movie (72k) Questions What is the shortest distance in which the horizontal belt can be brought to a stop without causing the crates to slide? What is the shortest distance for the inclined belt? Boxes Slides Click to view movie (126k) Approach Using Newton's Second Law, relate the forces acting on the crate with its acceleration. Analyze the problem in terms of rectangular coordinates. Since no sliding actually occurs, use the static coefficient of friction. Derive an equation for the position by integrating the acceleration equation a = d2x/dt2.