1-[IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image001.gif[/IMG] R
[IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image002.gif[/IMG][IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image003.gif[/IMG]يخضع S لقوتين :
[IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image004.gif[/IMG] - وزنه P
P
[IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image005.gif[/IMG] - تأثير السطح الأفقي R
-2 [IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image007.gif[/IMG]w(R)=
φ)/2+[IMG]file:///E:/DOCUME%7E1/ALLALI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image009.gif[/IMG]=R.AB cos( w(R
نعلم أن K=tang φيعني φ=11,3°
نجد w(R)= - 2,94 J