Whip (instrument)
There is another type of whip, in which one plank is longer than the other.  It can be played with one hand.  The player shakes the instrument quickly and the small plank moves away from the large one, then slaps back onto it.  It makes a different kind of sound from the whip, and is properly called a slapstick.   It has been used by several composers including Mahler, Richard Strauss, Ravel, Mussorgsky and Hindemith. The first whip was designed in the 14th century.