What is the angle of inclination relative to the horizontal called when an object resting on a slope is on the verge of sliding downward__________________?
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Answer: C. repose
Explanation
The angle of repose equals the maximum slope angle where an object remains stable. Exceeding this critical inclination causes gravity to overcome static friction initiating sliding. This angle matches the inverse tangent of the static friction coefficient. Granular materials and solid blocks form natural sloping piles limited by this angle. Sliding friction thresholds dictate when static stability transitions into dynamic motion. Horizontal components of weight balance limiting friction right at this threshold angle.
Geotechnical engineers use the angle of repose to design stable soil embankments. Bulk material storage silos rely on angle measurements to prevent unexpected avalanches. Mining operations monitor powder and rock pile angles for structural safety compliance. Option A names the general phenomenon rather than this specific geometric angle. Option B describes the maximum friction force value rather than a slope angle. Option D refers to friction during ongoing motion rather than impending slip conditions.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
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