F Vector is parallel to r vector formula ?

AI Thread Summary
The discussion revolves around the formula for the force vector being parallel to the position vector, expressed as F = F * (r / |r|). The user expresses confusion about how this relationship was derived, questioning the multiplication of the force unit vector by the unit position vector. Clarification is sought regarding the rationale behind this calculation. The conversation highlights the concept of vector projection and its application in this context. Understanding this relationship is essential for grasping the dynamics of forces in relation to position vectors.
thekey
Messages
14
Reaction score
0
Hi everyone( the force vector parallel to the position vector r ) = Force vector* (r vector / r)

I don't know how did they find this relation ?
it seems to me they multiplied F hat by the unit vector ?
why ??
I am just confused about it

any idea ??
 
Last edited:
Engineering news on Phys.org
F parallel hat= (F hat) * (r hat / r)
 
v101x.gif


the projection of v into the direction of u

0k that's why :)

thanks
 
Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
Back
Top