Question
In the dangerous "sport" of bungee-jumping, a daring studentjumps from a hot-air balloon with a specially designed elastic cordattached to his waist, as shown in the figure below. Theunstretched length of the cord is 25.0 m,the student weighs 695 N, and the balloonis 36.0 m above the surface of a river below. Calculate therequired force constant of the cord if the student is to stopsafely 3.0m above the river. i think i m using wrong formula or somethin because i m gettinwrong answer In the dangerous "sport" of bungee-jumping, a daring studentjumps from a hot-air balloon with a specially designed elastic cordattached to his waist, as shown in the figure below. Theunstretched length of the cord is 25.0 m,the student weighs 695 N, and the balloonis 36.0 m above the surface of a river below. Calculate therequired force constant of the cord if the student is to stopsafely 3.0m above the river. i think i m using wrong formula or somethin because i m gettinwrong answer
Explanation / Answer
given weight of the student is mg = 695N the balloon is at a height H = 36.0m above river which is the reference level, the student stops atheight H' = 3.0m the length of the cord is L = 25.0m using conservation of energy we get change in PE = spring energy mg(H-H') = 1/2*kx2 (here x = displacement ofcord) 695N(36.0m- 3.0m) = 1/2*k*(36m-3m-25m)2 simplify & calculate for k we get the force constantof the cord simplify & calculate for k we get the force constantof the cord