View Single Post
  #1   Spotlight this post!  
Unread 05-09-2007, 08:31
JoeXIII'007's Avatar
JoeXIII'007 JoeXIII'007 is offline
Pragmatic Strategy, I try...
AKA: Joeseph Smith
FRC #0066
Team Role: Alumni
 
Join Date: Feb 2004
Rookie Year: 2001
Location: Ypsilanti, MI (Ann Arbor's shadow)
Posts: 753
JoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond reputeJoeXIII'007 has a reputation beyond repute
Send a message via AIM to JoeXIII'007
Help on calc 3 problem would be incredibly appreciated...

ok... this problem is driving me nuts and I have till tomorrow (9/6/07) to figure it out.

It involves 3 dimensional vector math and dot products.

The task is to "find the magnitude of the projection of the load supporting cable OA (O being origin) onto the positive z-axis" as shown in a figure. The figure displays 3 vectors A, B, and C plus a 4th force vector going down the negative z-axis which is shown to have a force of 1000kg.

Points and their coordinates are as follows:

OA.) (10,5,20)
OB.) (-5,-5,20)
OC.) (5,-5,20)

From there, I am a bit stuck. I know the formula of any projection of u onto v... but it doesnt seem to me it would work in this case, it just doesnt seem right. Trig appears to me to be involved but how to apply it sort of stumps me for some reason.

Any help (hints, strategies, etc.) would be helpful and greatly appreciated... thanks!

-Joe
__________________
Joeseph P. Smith
jpthesmithe.com
University of Michigan - Informatics (B. Sci. 2012)
General Purpose Programmer - Cooperative Institute for Limnology and Ecosystems Research (CILER) at NOAA-GLERL
Reply With Quote