Pendulum, yoyo, Newtons Cradle, swing...
the particles in a surface water move back- and- forth only.
To move quickly back and forth.
solids
solid
that means reflections
I like to move back and forth on black sock went i am wiggled
the particles in a surface water move back- and- forth only.
the particles in a surface water move back- and- forth only.
After you stroke a tuning fork, all the particles move back and forth. If you play a piano, particles of the wire move back and forth.
solids
When something vibrates quickly, it has a higher than it does when it vibrates slowly
solids
it moves its body back and forth
solid
back and forth?
solid
To move quickly back and forth.