LARCALCET7 3.7.017.Ml. 8. [-/1 Points] At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 6 cubic feet per minute. The diameter of the base of the cone is approximately three times the altitude. At what rate (in ft/min) is the height of the pile changing when the pile is 22 feet high? (Hint: The formula for the volume of a cone is V = nrzh.) if]. = ft/min dt 9. [-/3 Points] LARCALCET7 3.R.119. A point moves along the curve y = J; in such a way that the y-component of the position of the point is increasing at a rate of 2 units per second. At what rate is the X-component changing for each of the following values? (a) X=i dx I (b) X=1 dx W 12. [-/2 Points] DETAILS LARCALCET7 3.R.094. The displacement from equilibrium of an object in harmonic motion on the end of a spring is 1 1 . =_cos 6t _sm 61' y 3 ( ) 3 ( ) where y is measured in feet and t is the time in seconds. Determine the position, in feet, and velocity v, in feet per second, of the object when t = g. ft '