## Friday, November 7, 2014

### EJSS primary school pendulum energy model

EJSS primary school pendulum energy model.
i have lost dropbox public folder and is unable to supply run-able links now.

 http://weelookang.blogspot.sg/2014/11/ejss-primary-school-pendulum-energy.html MODEL standalone: https://www.dropbox.com/s/20lc16lg3i2z25a/ejss_model_SHMxvapendulumpri.zip?dl=0 run: https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejss_model_SHMxvapendulumpri/SHMxvapendulumpri_Simulation.xhtml source: https://www.dropbox.com/s/675lfmdwur52m7p/ejss_src_SHMxvapendulumpri.zip?dl=0 author: lookang, anne cox author of EJSS 5.0 Francisco Esquembre

## The equations that model the motion of the pendulum system are:

this model assumes

$\frac{\delta \theta}{\delta t} = \omega$

$\frac{\delta \omega}{\delta t} = -\frac{g}{L}( sin \theta)$

where the terms

$L$ represents the fixed length of the pendulum

$g$ represents the gravity force component as a result of Earth's pull.

## Energy Equations:

this model uses

$PE = mg(y-y_{o}) = mgh$

where the terms
$PE$ represents potential energy of the mass m

$y_{o}$ represents the lowest point of the oscillation to facilitate conventions of positive values of PE.

$y$ represents the vertical height of the mass m

$KE = \frac{1}{2}mv^{2}$

$KE$ represents kinetic energy of the mass m

$v$ represents the velocity of the mass m

$TE = PE + KE$

$TE$ represents the total energy of the mass m.