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

Answer:

The force is $F_b = 216 \ N$

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

    $F_b = F - W$

=>    $F_b = 100 - 784$

=>  $F_b = 216 \ N$