Period is defined as the time required to complete one cycle which is also related to frequency. Period is presented by an equation P = 1/f where p is the period, and f is the frequency. The unit is in second. Frequency is defined as the number of circular revolutions in a given time interval and it is in Hertz (Hz) = 1s^-1. Velocity s defined as the arc traveled at a given time with the equation v=l/t where v is the velocity, l is the length and t is time. The unit is in m/s.