Question

An 80-kg bungee jumper jumps off a bridge. Rubber bungee cords act as a large spring attaching the jumper to the bridge. A bear standing in the river below catches the jumper. If the spring constant of the bungees is 20 N/m and they stretch 50 m. How much force must the bear apply to keep the jumper from moving?

Answer 1

The force is
`F_b =  216 \  N`

Step-by-step explanation:

From the question we are told that

The mass of the bungee jumper is m = 80 kg

The spring constant is
`k = 20 \ N/ m`

The extension of the rubber bungee cords is x = 50 m

Generally the weight of the jumper is

`W =  m *  g`

=>
`W =  80 *  9.8`

=> tex]W = 784 \ N [/tex]

Generally the returning force of the rubber bungee cords is mathematically represented as

`F  =  k  *  x`

=>
`F  =  20   * 50`

=>
`F  =  1000 \  N`

The force to be applied by the bear is

`F_b =  F -  W`

=>
`F_b =  100 -  784`

=>
`F_b =  216 \  N`