1) A cylindrical riser is to be designed for a sand casting mold. The length of the cylinder is to be 1.25 times its diameter. The casting is a square plate, each side = 10 in and thickness = 0.75 in. If the metal is cast iron, and the mold constant = 16.0 min/in² in Chvorinov's rule, determine the dimensions of the riser so that it will take 40% longer time for the riser to solidify.

2) The foreman in the injection molding department says that a polyethylene part produced in one of the operations has less shrinkage than the calculations indicate it should have. The important dimension of the part is specified as 111.5 0.25 mm. However, the actual molded part measures 112.02 mm. (a) As a first step, the corresponding mold cavity dimension should be checked. Compute the correct value of the mold dimension, given that the shrinkage value for polyethylene is 0.025 (from Table 8.1). (b) What adjustments in process parameters could be made to increase the amount of shrinkage (read Section 8.6.3 to find at least 3 adjustment options)?