Question

40 POINTS. When they form conical piles, granular materials such as salt, gravel, and sand settle at different "angles of repose," depending on the shapes of the grains. One particular 13-foot tall cone of dry sand has a base diameter of 38.6 fee

To the nearest tenth of a degree, what is the angle of repose of this type of dry sand?

A different conical pile of the same type of sand is 10 feet tall. What is the diameter of the cone's base?

Henley Landscaping Supply sells a type of sand with a 30° angle of repose for $32 per cubic yard. Find the cost of an 11-foot-tall cone of this type of sand. Show your work.

Answer 1

34.0 degrees, 29.6 feet in Diameter.

This is a right triangle trigonometry question.

Use half of the diameter to form the base of the triangle (19.3 ft) with a height 0f 13.

Use Inverse Tangent function to find the angle of repose

round to 34.0

then use the angle of repose to solve trigonometric function of the tangent for the radius of the other cone.

switch denominator and tangent

multiply by 2 to get diameter of second cone

14.82*2≈29.6

hopefully this helps!