A logistics technician is tasked with repositioning a large, heavy equipment pod across a flat warehouse floor. Rank the following movement scenarios in order from the greatest magnitude of frictional resistance to the least magnitude of frictional resistance.
- 1Breaking the pod loose from a stationary position to start it sliding across the dry floor.
- 2Maintaining a steady sliding motion of the pod across the dry floor.
- 3Maintaining a steady sliding motion of the pod across a section of the floor coated with heavy grease.
- 4Moving the pod continuously at a steady speed after mounting it on heavy-duty wheeled dollies.
Answer
The correct sequence from greatest to least resistance is: breaking the pod loose from a standstill (static friction), sliding continuously on a dry floor (kinetic friction), sliding continuously on a greased floor (lubricated friction), and moving the pod on wheeled dollies (rolling friction).
In mechanical systems, friction types follow a general hierarchy of resistance. Static friction (starting motion) is the highest because surfaces settle and interlock. Kinetic friction (dry sliding) is lower than static but still high due to direct surface scraping. Introducing a lubricant reduces this direct contact, lowering resistance further. Finally, replacing sliding motion with rolling motion (using wheels) typically offers the lowest resistance because the contact point rolls over the surface rather than dragging across it.
Step-by-Step Solution
Key Concept
Types and Magnitudes of Mechanical Friction
Estimated Time:45s