Sand dunes at Stockton Beach

The inspiration for this topic came from my visit to the sand dunes at Stockton Beach near Anna Bay, just north of Newcastle. I became interested in the slope at which the sand could remain stable. After further investigations, I found that this was called the angle of repose. The following is a definition of angle of repose from Massachusetts Institute of Technology.

Angle of repose: The maximum angle at which a pile of unconsolidated material can remain stable. From Massachusetts Institute of Technology

To understand more about the angle of repose, I conducted experiments to measure the angle of different particles. To do this, I used equipment and materials found in the kitchen, so I gave the four experiments the name of "Kitchen Experiments." The particles used in these experiments were rice and mung beans.

The second part of the study involved the scientific knowledge related to the angle of repose. Apart from looking at the forces operating on the slope, I also studied the factors affecting the angle.

After that, I conducted another series of experiments to see how angles of repose are affected by different factors. These factors included particle size, roundness of particles, and dampness. The particles used in these experiments were sand and gravel.

The final section of my report is called "Angle of repose everywhere." I found examples with illustrations on angles of repose in both the natural and human environment.


The following are more definitions of angle of repose from different sources:

The maximum slope at which a heap of any loose or fragmented solid material will stand without sliding or come to rest when poured or dumped in a pile or on a slope.         From the Dictionary of Mining, Mineral, and Related Terms, Hacettepe University Dept. of Mining Engineering The steepest angle of slope that a "cohesionless" material will form. The angle is measured from the horizontal.         From Department of Geosciences, University of Arizona Angle of repose (Physics), the inclination of a plane at which a body placed on the plane would remain at rest, or if in motion would roll or slide down with uniform velocity; the angle at which the various kinds of earth will stand when abandoned to themselves.         From Webster's Revised Unabridged Dictionary (1913) The maximum angle from horizontal at which a given material will rest on a given surface without sliding or rolling.         From Mineral Science Technology, R. D. Parker Collegiate, Thompson, Manitoba, Canada