When it vibrates in several sections, each section moves in the opposite way to its neighbours.
This hammer is arranged so that when the armature vibrates it gives little blows to the underside of the tube and shakes up the filings.
Lay the compass upon the cardboard, and observe the rate at which its needle vibrates after being displaced from its position of equilibrium; this will vary greatly in different regions.
I) be a small portion of a bell which vibrates to and fro from CD to EF and back.
The two forks are fixed so that one vibrates in a vertical, and the other in a horizontal, plane, and they are so placed that a converging beam of light received on one mirror is reflected to the other and then brought to a point on a screen.