18 Paragraph for Two tennis balls of mass 60 gmare attached

Last updated: 6/8/2023

18 Paragraph for Two tennis balls of mass 60 gmare attached with a massless rubber thread and held in the vertical position as shown in the fig In this position length of the rubber thread is 40 cm and it is un stretched The upper ball is slowly raised vertically upward until the lower ball just becomes unsupported by the ground At this time the length of the thread is 1m The rubber thread exerts a force which is proportional to its extension 17 What is the force constant of the rubber cord A 2 N m B 1 N m C 0 5 N m D 0 25 N m How much work is done by external agent while the upper ball was raised A 0 54 J B 0 36 J C 0 18 J D 0 45 J 18