10. The coefficient of kinetic friction between a rubber tire and a wet concrete road is 0.5. (a) Find the minimum time in which a car whose initial velocity is 50 km/h can come to a stop on such a road. (b) What distance will the car cover in this time?

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.