An elastic bungee cord can be modeled as an ideal spring with spring constant
PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
An elastic bungee cord can be modeled as an ideal spring with spring constant k=150Nm−1. The unstretched length of the cord is defined as Δx=0. A 70kg jumper steps off a platform and, at the lowest point of the jump, the cord is stretched downward by 1.80m. Air resistance is negligible.
(a) Calculate the elastic potential energy stored in the cord when it is stretched by 1.80m.
(b) On the axes below, sketch a graph of the cord’s elastic potential energy U (vertical axis) versus stretch Δx (horizontal axis) for 0≤Δx≤2.0m. Label the value of U at Δx=1.80m calculated in part (a).
(Provide a clear verbal description of your sketch in your response.)
(c) Using your graph, determine the additional amount of elastic potential energy stored as the stretch increases from 1.40m to 1.80m. Show how the graphical representation supports your numerical result.