How do you find the velocity of a wave?

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

What part of the ear is names after tools, such as the hammer and the anvil?

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?