1) In a multi-cavity injection molding, two cavities are filled with a polymer melt, where the volume of cavity 1 is 4 times cavity 2:V1=4V2. To achieve equal part quality, the filling time for both cavities must be balanced. We assume that the polymer melt is a Newtonian liquid and the runner systems to both cavities are tubular and have the same length: (a) if both plasticating units provide the same pressure, what should be the ratio of R1 (radius of runner to cavity 1 ) to R2 (radius of runner to cavity 2 )? (b) if both runner systems have the same radius, R1=R2, what should be the ratio of P1 (pressure generated by plasticating unit 1) to P2 (pressure generated by plasticating unit 2)? (c) Since polymer melts do not usually behave Newtonian under injection molding shear rates, how will predictions in part (a) for R1/R2 ratio and in part (b) for P1/P2 ratio be affected? 1) In a multi-cavity injection molding, two cavities are filled with a polymer melt, where the volume of cavity 1 is 4 times cavity 2:V1=4V2. To achieve equal part quality, the filling time for both cavities must be balanced. We assume that the polymer melt is a Newtonian liquid and the runner systems to both cavities are tubular and have the same length: (a) if both plasticating units provide the same pressure, what should be the ratio of R1 (radius of runner to cavity 1 ) to R2 (radius of runner to cavity 2 )? (b) if both runner systems have the same radius, R1=R2, what should be the ratio of P1 (pressure generated by plasticating unit 1) to P2 (pressure generated by plasticating unit 2)? (c) Since polymer melts do not usually behave Newtonian under injection molding shear rates, how will predictions in part (a) for R1/R2 ratio and in part (b) for P1/P2 ratio be affected