The first observation of injection locking was in two of these devices. For these devices, the Airy condition can be approximately satisfied by deadbeat escapements. (20[1])A classic example of a control system with a cart-pole apparatus involves maintaining (0[1])the stability of an “inverted” one of these (20[1])devices. (20[1])Harmonographs (20[3])draw Lissajous (20[3])(“LEASE-ah-zhu”) curves (20[1])from (20[1])the motion of these devices. (20[6])(*) Angular (10[1])velocity is proportional to the sine (10[1])of latitude (0[1])in a type of these devices that provided the first evidence of the Earth’s (10[2])rotation. (10[6])The (10[1])small angle approximation (10[1])equates (10[1])two pi (10[1])times the square root of length (10[1])over little g to the period of one of these devices. (10[1])For 10 points, name these devices that consist of a suspended mass swinging from a fixed (10[1])point. ■END■ (10[1])