Homework Question: In a system with two degrees of freedom, mass is M1=0.25 MNs2/m+student number last digit, M2=0.125MNs2/m+ student number last digit, spring stiffness is k1= 60MN/m+ student number is first digit, k2=40MN. /m+ the first digit of student number. Then; m2 k2 X2 X1 m1 a) Determine Natural Frequencies and Mode shapes. b) Calculate the earthquake force using the mode combination method using the spectrum curve below. k1 Salg S/g=(0.1+T)e Time Period, T (sec)