Aboat is traveling east at a speed of 3.8 m/s. a person walks across the boat with a velocity of 1.3 m/s south. a. what is the person’s speed relative to the water?
b. in what direction, relative to the ground, does the person walk?

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?