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brandy
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Homework Statement
when powder or granular solids are piled up. the powder forms a conical pile. the edge of the pile reaches a certain maximum angle with the horizontal, called the angle or repose.
A) a pile of coal is found to have an angle of repose of 38%
what is the relationship between height of the pile and its radius.
i got that bit: h=r*Tan a
h= height, r=radius a= Angle of repose
B)if a conveyor belt pours the coal onto the pile at a rate of 0.3m^3/min, at what rate is the radius increasing when the radius is 1.7m
i think i might have to derive the equaiton but i really don't know. i think i need the formula for the area of cone but i don't know. if i did i wouldn't be posting here!