A spring is hung from the ceiling. A 0.410-kg block is then attached to the free end of the spring. When released from rest, the block drops 0.126 m before momentarily coming to rest, after which it moves back upward. Required:

a. What is the spring constant of the spring?

b. Find the angular frequency of the block 's vibrations.

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?