A small stone, of mass 0.2 kg, tied to a massless, inextensible string, is rotated in a vertical circle of radius 2 m

A small stone, of mass 0.2 kg, tied to a massless, inextensible string, is rotated in a vertical circle of radius 2 m. If the particle is just able to complete the vertical circle, what is its speed at the highest point of its circular path ? How would this speed get effected if the mass of the stone is increased by 50% ? (Take g = 10 ms’2)