A car drives from mile marker 45 mile marker 100 and 0.7 hours then the car turned around and drives tomorrow marker 20 in one hour what is the average velocity of the car

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. they are charged to ±10 nc. what is the electric field strength between the disks? a proton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?