======Angle of Repose======


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**Alternative titles:** Determining the Flow Properties of Powders
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====Summary====                   
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====Procedure====  
  - Prepare several samples of sand with different particle sizes or mixtures.  
  - Place each sample in a cylinder or container with a removable base.  
  - Lift the cylinder vertically, allowing the sand to flow freely and form a heap on a flat surface.  
  - Measure the height and base diameter of the heap using a ruler.  
  - Calculate the angle of repose using the formula:  
    θ = tan⁻¹(height / radius)  
  - Repeat the process for each sand type, including one with added moisture or glidant.  
  - Record all measurements and compare the calculated angles to assess flow properties.



====Links==== 
Angle of Repose | Determination of Angle of Repose With Calculation | Angle of Repose - Solution- Pharmacy: 
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ANGLE OF REPOSE | HOW TO PERFORM IN LABORATORY? DETAIL CALCULATION | IMPORTANCE OF FLOW PROPERTY - PHARMAROCKS THE WAY OF SUCCESS: 
{{youtube>rPCOUitcOV4?}}\\

📄 Angle of Repose - Pharmaceutical Technology: [[https://pharmatechno2014.blogspot.com/p/d-angle-of-repose.html]]\\


====Variations====
  * Repeat the experiment using different powders.  
  * Compare dry and slightly damp samples to examine the effect of moisture.  
  * Use mechanical methods such as a tilting box or revolving cylinder to measure dynamic angles of repose.



====Safety Precautions====
  * Work on a clean, stable surface to prevent spills or contamination.  
  * Handle glassware and measuring tools carefully.




====Questions to Consider====
  * Which sand sample had the lowest angle of repose, and what does that indicate? (A lower angle indicates better flowability.)  
  * How does particle size affect flow characteristics? (Smaller particles increase cohesion, leading to higher angles of repose.)  
  * What is the effect of adding moisture or glidant? (Moisture increases cohesion and the angle of repose, while glidants reduce it.)  
  * How does particle shape influence the results? (Round particles roll more easily and form lower angles than irregular ones.)  
  * What alternative methods can be used to measure angle of repose? (Tilting box, fixed funnel, or revolving cylinder methods.)