text: what is the period of oscillation? a bob of mass m is suspended from a string of length l, forming a pendulum. the period of this pendulum is 2.2 s. if the pendulum bob is replaced with one of mass m and the length of the pendulum is increased to 2l, what is the period of oscillation? the relation is predicted to be: t = 2pie (l/g)0.5 where g = 9.8,   this website appears to be very helpful. http://www.exo.net/~pauld/activities/pendulums/pendulums.html#where  hope this helps=)