# Find parallel vector component

1. Jan 6, 2012

### blackandyello

1. The problem statement, all variables and given/known data

Resolve the position vector A of the car (measured from fixed point O)
into components parallel to OB and OC.

Figure: http://screensnapr.com/e/4D2OAz.png [Broken]

2. Relevant equations

Projection of vector A to OC = |A| * |unit vector OC| * unit vector

3. The attempt at a solution

my solution for finding the component parallel to OC is by finding the angle of triangle AOC, then use that angle to compute for parallel component at OC. my answer ended up to be the same 3500m. but the book says, 2570m along OC.

Last edited by a moderator: May 5, 2017
2. Jan 6, 2012

### humanist rho

A.B = ABCosθ is the projection of vector A along B.

3. Jan 6, 2012

### JHamm

But if you take $B = A$ then you find the projection of $A$ along $A$ is $A^2$

4. Jan 6, 2012

### humanist rho

oh sorry. I mean B cosθ is the projection of B along A.