EJSS Vertical Spring-Mass (N08/III/6) Model

EJSS Vertical Spring-Mass (N08/III/6) Model by Lee Tat Leong and Ng Kar Kit.

http://weelookang.blogspot.com/2014/12/ejss-vertical-spring-mass-n08iii6-model.html
run: https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/lookangejss/00workshop/ejss_model_verticalSpringMass_N08P3Q6/verticalSpringMass_N08P3Q6_Simulation.xhtml
source: https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/lookangejss/00workshop/ejss_model_verticalSpringMass_N08P3Q6.zip
author: Lee Tat Leong and Ng Kar Kit.
author EJS: Paco

The model

Spring: spring constant k = 19.62 N/m, natural length of spring Lo = 0.650 m, equilibrium length yo = 0.850 m

Load: mass m = 0.400 kg, displacement from equilibrium position y

Mathematical model:

δyδt=vy

δvyδt=−k(y0+y)m+g

Energies:

kinetic energy (green)

KE=12mv2y
elastic potential energy (red)

EPE=12k(yo+y)2
gravitational potential energy (blue)

GPE=mg(Lo+yo+y+referencelevel)
total potential energy (magenta)

TPE=EPE+GPE elastic and gravitational potential energy,
total energy (black)

TE=KE+EPE+GPE sum of all the energies

Controls:

The gravitational potential energy is calculated with respect to the reference level (blue horizontal line). This reference level can be adjusted by (1) dragging the blue box at the right end of the reference level or (2) entering the value of the position in the text box at the lower right hand corner.

fine < > control buttons for learners to manipulate the model with single incremental precision
Reset button to bring simulation back to original (default)setting.