One end of string of length 1.5 m is tied to a stone of mass 0.4 kg and the other end to a small pivot on a smooth vertical board. What is the minimum speed of the stone required at its lowermost.point so that the string does not slack at any point in its motion along the vertical circle ?

One end of string of length 1.5 m is tied to a stone of mass 0.4 kg an

1.	One end of string of length 1.5 m is tied to a stone of mass 0.4 kg and the other end to a small pivot on a smooth vertical board. What is the minimum speed of the stone required at its lowermost.point so that the string does not slack at any point in its motion along the vertical circle ?
Answer» Solution :The MINIMUM SPEED of the stone REQUIRED at its lowermost so that the STRING does not slack at,any point = `v_("min") = sqrt(5gR)`.[See derivation under MOTION in a vertical circle.] `v_("min") = sqrt(5 xx 9.8 xx 1.5) = 8.57 ms^(-1)`