ENGR 8
Part I. Drills -- 1 point each
Assignment 2
Due: next wed
Part II. Assisted Problem Solving – 2 pts each
PLAN
Notice that this is the reverse of the normal sequence
where we find a position vector and convert to force
vector. Here, we are given force vector and need to find
position vector so we can determine the x, y and z of the
pole. Notice also that F is pointing toward the origin
whereas our position vector will need to point away.
1) Find the unit vector in the F direction
2) Negate this vector and scale up by the length of
the cable to get r, the position vector to the pole
3) The x, y, and z of the position vector are your
answers.
PLAN
1) First find the position vector rOa and then
determine the unit vector along the Oa axis.
2) The component of F along Oa would then be
FOa = F . uOa
3) The component of F perpendicular to Oa would be
F – FOa
Part III. Unassisted Problem Solving – 3 points each