How much height does the stone fall when it gains the speed of 3.6 m/s?

A light string is wrapped around the outer rim of a solid disk of diameter 100.0 cm and mass 12.0 kg that can rotate without friction about an axle through its center. A 3.00 kg stone is tied to the free end of the string, which is at some height above the ground, as shown in the figure. When the system is released from rest. how much height does the stone fall when it gains the speed of 3.6 m/s? Moment of inertia of the disk. / = = MR. [Use the conservation of energy) The number will come as a whole number. (Hint: you need to find yj from the boxed equation we found in class]