A sled at rest is suddenly pulled in three horizontal directions at the same time, but it does not move. Paul pulls to the northeast with a force of 31 lb. Johnny pulls at an angle of 36° south of due west with a force of 52 lb. Connie pulls with a force to be determined.
1) Express the boys' two forces in terms of the usual unit vectors
2)Determine the third force (from Connie), expressing it first in component form and then as a magnitude and direction (angle). Neglect friction.
1 answer
component of paul force:31cos45i+31sin45j=21.9i+21.9j component of johny force:52cos216i+52sin216j=-42.1i-30.6j Connie force is the resultant=21.9i+21.9j-42.1i-30.6j=-20.2i-8.7j direction=arctan(-8.7/-20.2)=23.3degree Fmag=sqrt(20.2^2+8.7^2)=21.99N
1 answer