A ball is projected upward at an initial velocity of the ball is 80.5 m/s, from a point on a flat roof 90 m above the ground. The ball rises and then falls missing the roof, and strikes the ground. Find the vertical velocity of the ball when it is 89 m above the ground is closest to

a. -81
b. -64
c. -48
d. -32
e. -97

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?