Observations
1 If ˆp  is the unit vector along a line l, then the projection of a vector ar  on the line
l is given by 
a pˆ
r 2 Projection of a vector ar  on other vector b
r , is given by
a bˆ,
r⋅
   or   
,  or  1
(
)
|
|
|
|
b
a
a b
b
b
⎛
⎞
⋅
⋅
⎜
⎟
⎝
⎠
r
r
r
r
r
r
3