A 10.0 kg mass is attached to the end of a 2.00 m long brass rod, which has a diameter of 1.00 mm and negligible mass. The mass at the end is pulled, stretching the rod slightly, and then released. If the elastic modulus of brass is 9.10 × 1010 N/m2, then the period of the resulting oscillations is A. 0.175 sec.
B. 0.105 sec.
C. 0.133 sec.
D. 0.145 sec.
E. 0.167 sec.

Two conductors, a and b, are each in the shape of a tetrahedron. but of different sizes. they are charged in the following manner: 1. tetrahedron a is charged from an electrostatic generator to charge q. 2. tetrahedron a is briefly touched to tetrahedron b. 3. steps 1 and 2 are repeated until the charge on tetrahedron b reaches a maximum value. if the charge on tetrahedron b was q/4 after the first time it touched tetrahedron a. what is the final charge qbmax on tetrahedron b?