A car is stopped at a traffic signal. A second car rear-ends the first car. From the crush of the two vehicles, it is estimated that the second car was traveling at 15 mph when it impacted the first car. If the second car laid down 166 feet of skid marks before the crash took place, how fast was the second car traveling when its brakes were locked up

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?