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

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