A stone of m ass m tied to the end of a string revolves in a vertical circle of radius R. The net force at the lowest and highest points of the circle d irected vertically dow nw ards are : [Choose the correct alternative] Lowest Point (a) mg - T_(1)(b) mg + T_(1) (c) mg + T_(1) - (mv_(1)^(2))//R (d) mg - T_(1) - (mv_(1)^(2))//R Highest Point mg + T_(2) mg - T_(2) mg - T_(2) + (mv_(1)^(2))//R mg + T_(2) + (mv_(1)^(2))/R T_(1) and denote the tension and speed at the lowest point. T_(2) and v_(2) denote corresponding values at the highest point.

A stone of m ass m tied to the end of a string revolves in a vertical

1.	A stone of m ass m tied to the end of a string revolves in a vertical circle of radius R. The net force at the lowest and highest points of the circle d irected vertically dow nw ards are : [Choose the correct alternative] Lowest Point (a) mg - T_(1)(b) mg + T_(1) (c) mg + T_(1) - (mv_(1)^(2))//R (d) mg - T_(1) - (mv_(1)^(2))//R Highest Point mg + T_(2) mg - T_(2) mg - T_(2) + (mv_(1)^(2))//R mg + T_(2) + (mv_(1)^(2))/R T_(1) and denote the tension and speed at the lowest point. T_(2) and v_(2) denote corresponding values at the highest point.
Answer» Solution :Whenstoneis tieldat endof stringand whirledin CIRCULARPATH inverticalplaneletH behighestpointand L belowest POINT AtpointL : Tension`T_(1)`towardcentreand weigth mg isin downwarddirection Resultantforceactingon STONEIS indownwarddirection Resultantforce=mg= `T_(1)` At pointH : Heretensiion `T_(2) `and weightmg Henceoption( A)iscorrect.