[填空题]
A block of jello rests on a plate r( 06m ma4k0i:f d4 zc6v kpm;bks,i(ved8ydmas shown in Fig. 11–58 (wmbxzx+ m*zz s)gx)6 +which also gives the dimensions of the block). You push it sideways as shown, and then you let go. The jello springs back and begins to vibrate. In analogy to a mass vibrating on a spring, estimate the frequency of this vibratibm*6mgs x)+z x +zxzw)on, given that the shear modulus (Section 9–5) of jello is 520 $N/m^2$ and its density is 1300 $kg/m^3$ Hz
