APS Excellence in Physics Education Award
November 2019

Education Prize Logo
Science SPORE Prize
November 2011

NSF Logo
The Open Source Physics Project is supported by NSF DUE-0442581.

Physics of Maximum Amplitude versus Driving Frequency Question made in EJS

Return to the EJS Modeling forum
Login to post to this thread

Physics of Maximum Amplitude versus Driving Frequency Question
lookang Avatar
lookang
222 Posts

Physics of Maximum Amplitude versus Driving Frequency Question referring an original model found in EJS examples found in.....\source\users\davidson\wochristian\osc\SHOResonance.xml

Dear Prof Wolfgang,

i am puzzled as to the correct ODE equation for the driving force's acceleration component.

is it

+A*Math.cos(omegaD*t)/m 

or

+A*Math.sin(omegaD*t)/m .

 

the resultant plots for +A*Math.cos(omegaD*t)/m starts at Amplitude =1 which is what i believe is correct but it does not have the maximum curve characteristics (see picture) 

 

for case 2: the resultant plots for +A*Math.sin(omegaD*t)/m starts at Amplitude =0 which is what i believe NOT correct but it has the maximum curve characteristics (see picture).

 

Any advise how i can model the driving force such that

1) start at Amplitude= 1 (usually we teach with a non-zero value in our lecture notes)

2) has the desired maximum curve characteristics which exists in our teaching materials (usually we do teach this feature).

 read more:

http://weelookang.blogspot.sg/2014/03/ejs-resonance-frequency-vs-amplitude.html

 

model DL here

https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejs_model_SHOResonancewee.jar

 

source is also attached for consideration into the OSP collection please

 

thanks!

Post edited March 19, 2014 at 11:04 PM EST.

Attached File: ejs_src_SHOResonancewee.zip


OSP@SG blog
OSP@SG Digital Library

Current Replies - View all
Re: Physics of Maximum Am...   (Wolfgang - )
OSP Projects:
Open Source Physics - EJS Modeling
Tracker
Physlet Physics
Physlet Quantum Physics
STP Book