Thus, it can be seen that clay soils exhibit the worst case for drawbar 

 pull requirements. 



In order to determine the power required to vibrate the plow (the 

 feed shoe is isolated from the plowshare to prevent cable damage and 

 reduce power requirements for vibration) , consider a vibrating mass 



X = A sin 0) t 



where A = the amplitude 

 0) = the frequency 



Then 



X = A 0) cos u) t 



■A CO sin 00 t 



Instantaneous power is given by 



P = Fv = mxx 



.2 3 . 



= - m A u sm u t cos co t 



P = 



a2 3 



A CO 



sin 2 0) t 



The power which must be supplied is the root mean squared power, or 



- u 



p^dt 



where the period T = 1 /f = 2 tt/u) 

 2Tr/(jo / 



- f 



a2 3 



m A oj 







2 

 sin 2 to t dt 



1/2 



1/2 



277 /co 



sin 2 CO t dt 



58 



