What is the relationship between the perpendiculars in a 3D vector?

[lionely]

Homework Statement

I'm confused ,here's ... my attempt..

all I know so far is the

the k component would be 5...
I have no idea what to do with the i and j

 

[tiny-tim]

hi lionely!

all I know so far is the

the k component would be 5...
I have no idea what to do with the i and j

drop perpendiculars DP and EQ onto the base …

where are P and Q in relation to ABCD ? ​

 

[SteamKing]

Hint: Assume DE is located such that its midpoint is positioned directly over the intersection of the base diagonals OB and AC.

 

[lionely]

Hmm is DE is assumed to be at the mid point then.. for the j component that would be 4j

but the i? ... umm is it like the base below DE is 8 because DE is 6cm and OA is 14? so 14-6?

 

[lionely]

hi lionely!


drop perpendiculars DP and EQ onto the base …

where are P and Q in relation to ABCD ? ​

when I dropped the perpendiculars they ended up being at the midpoints of the widths of the base

 

[Chestermiller]

Hmm is DE is assumed to be at the mid point then.. for the j component that would be 4j

but the i? ... umm is it like the base below DE is 8 because DE is 6cm and OA is 14? so 14-6?

You had your answer in this post, but didn't realize it. 14 - 6 = 8, and this difference is split evenly between between the two sides. So the i component is 4.

 

[tiny-tim]

hi lionely!

(just got up :zzz:)

when I dropped the perpendiculars they ended up being at the midpoints of the widths of the base

(we'll call them P and Q)

ok … so the next line in your proof would be to say what the distance PQ is

and then you can compare that with the length of the base