Question

A bungee jumper wishes to test the elasticty of their bungee rope. They attach a known weight of 25.0 kg to the end of the rope and measure a 1.0 m extension of the rope. if the bungee jumper eights 85.0 kg, is 2.1 m tall and the bridge they wish to jump off is exactly 50 m above a concrete highway, how long should the rope be if they wish to survive the experience?

Answer 1

stretch of the rope 25 kg for 1m

elastic const. of the rope = 25g N/m

When the person weighing 85 kg , the force on the rope = 85g N

stretch of the rope = 85g /25g = 3.4 m

The jumper jumps the rope would stretch by 3.4 m

height of the jumper 2.1 m

total 5.5 m

Height of the jump = 50 m

The rope shall be 50 - 5.5 = 44.5 m, so that the jumper just touches the floor of the road and bounces back with the rope without hurting himself.