Download ModelDownload SourceembedFeedback


Bungee Jump Intro

Bungee Jumping

Bungee Jumping Photo Courtesy of Lilly M, Wikimedia Commons.

Bungee Jumping is a thrill seekers adventure that also allows for an investigation of energy concepts including Kinetic Energy, Gravitational Potential Energy and Elastic Potential Energy. Gravitational Energy (determined by height above the ground) is converted into Kinetic Energy until the slackness in the bungee cord is taken up. When the jumper reaches the end of his rope, there is an interplay between the three types of energy until Kinetic Energy reaches zero .

In this simulation, a bungee jumper is dropped from a tower with a fixed length of bungee cord. The simulation operator can control the height of the tower, the stiffness of the bungee cord (determined by its spring constant k), the unstretched length of the bungee cord and the jumper's mass. The player buttons are the play/pause button, the rewind (to t=0) button and the reset button (resets all parameters to initial values). The operator may optionally display the forces acting on the jumper and a plot of the g-forces versus time. Note that the simulation measures the altitude in terms of the location of his feet, thus he hits the ground if his feet get within his 1.7m of height to the ground.

When trying for a minimum drop from a platform set for h = 10 m, the jumber will hit the ground. The impact is represented by a red cross symbol blocking our view of the "accident".

Start by setting the platform hieght to its minimum (h=10m), the spring constant of the bungee cord to its stiffest setting (k=200 N/m), the length of the bungee cord to its minimum (Lo=5m) and the jumper's mass to its minimum (m=40kg). Through trial and error determine the minimum platform height needed for a "safe" jump.

  • Play the simulation with these safe jump settings and watch the interplay between the various types of energy. Does the total energy change?
  • Are the g-forces experienced by the jumper reasonable, dangerous or even fatal?

With our "safe" jump settings above, consider the effect of the following on the saftey of the jump:

  • increasing/decreasing the jumper's mass,
  • increasing/decreasing the unstretched length of the cord,
  • increasing/decreasing the stretchiness of the bungee cord (by decreasing/increasing k)
  • What kind of changes do you think the jump operator should make in order to accomodate a heavier jumper after a succesful jump by a lighter jumper?

For a 40 kg jumper and a 30 m platform height and a "safe" jump,

  • determine the longest (Lo) bungee cord that can be used for the stiffest bungee cord (k=200N/m)
  • for the shortest bungee cord (Lo=5m) determine the least stiff springiness (smallest k)
  • compare these two ride experiences from the jumper's perspective (look at g-force!)

Joomla! Debug Console

Bungee Jump