Pendulum not SHM? Virtual Lab

About
An open source physics at Singapore simulation based on codes written by Francisco Esquembre and Loo Kang WEE.
more resources can be found here
http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/09-oscillations

Introduction
Is pendulum motion of a mass oscillating about a fixed point on a mass-less string under a retarding force proportional to the amount of displacement from an equilibrium position?
It turns out that a pendulum is only appropriately a simple harmonic motion with the angular displacement is small. How small? play with the app and it turns out to be roughly less than 10 degree from the vertical plumb line.

Interesting Fact
This app is produce real numbers to coincident with the real world data.

Acknowledgement
My sincere gratitude for the tireless contributions of Francisco Esquembre, Fu-Kwun Hwang, Wolfgang Christian, Félix Jesús Garcia Clemente, Anne Cox, Andrew Duffy, Todd Timberlake and many more in the Open Source Physics community. I have designed much of the above based on their ideas and insights.
This research is supported by the eduLab project NRF2015-EDU001-EL021 , awarded by the Prime Minister Office, National Research Foundation (NRF), Singapore in collaboration with National Institute of Education (NIE), Singapore and the Ministry of Education (MOE), Singapore.
reference:
http://edulab.moe.edu.sg/edulab-programmes/existing-projects/nrf2015-edu001-el021

Network Learn together?
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