A 9402-kg rail flatcar moving forward at 0,65 m/s strikes a stationary 18086-kg boxcar, causing it to move forward at 0,51 m/s. What will be the velocity of the flatcar immediately after collision if they fail to connect?

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?