31 



rcnultn forces is lOlbs., one of then is 



Slbs., mi'i t: 



mt at on angle of 30". 1 



Jbmft. Sin- 1 ^(10 -2 N 



nt of two forces P, <?, acting at an angle 0, 



is ojual t. <.'/;< i s /" f '/ ; wh.-n t!,, v ad al H 

 i?r-0, it is i-ijual to (1m - 1) V(P* + <f) I shew 



-=.*; 



r 1 



forces F and F' acting in the diagonals of a 

 paral!eloffram keen it at rest in such a position that one of iu 

 edges is norisoiita), shew that 



Fscc a' - F' see a - TTcosec (a 4- a*), 



f the parallelogram, a and a' the 

 - between its diagonals and the horizontal - 



8. If a particle be placed on a sphere, and be acted on 



forces r and direction by 



mutually at right angles drawn through the 

 i at rest. 



Three forces P, Q> It n< and ke 



resented by straight line* drawn I 



in magnitude m. 



itu<U 01 loctia of the extremity uf the 



iird fore 



. A q IK re. 



le whose plane is vertical has a centre of con- 

 ice at one c.\ -f the hociiontal dia- 



. 



: >rce being equal to the wcL 



thr \ 



Ittitult. T viih the 



ikes an angle of 60* with the horiion. 



