Awooden crate of mass m = 70 kg slides horizontally off the back of a flatbed truck traveling at 80 km/hr. determine the kinetic coefficient of friction between the road and the crate if the crate slides (without tumbling) a distance of d = 50 m on the ground before coming to rest. assume the initial speed of the crate is the same as that of the truck.

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?