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Choosing directions, vectors

  • #1
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Homework Statement

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Homework Equations

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The Attempt at a Solution


When I have to describe a motion i'm supposed to decompose a vector in two directions, for example in an inclined plane is decompose the weight in these directions: the normal to the plane and the parallel to the plane, and that seems logic, but could I decompose the weight in other directions? The same thing for the velocity in a parabolic motion, I decompose the velocity in the vertical and the horizontal directions because it is easier but could I describe the motion using other directions?for example the horizontal and another one inclined with the horizontal by an angle different of 90 ?

I think I could because it's a matter of choice, the motions doesn't change, changes just the way you look at it
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Answers and Replies

  • #2
Mister T
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You are free to make these choices. Often you can turn a difficult problem into an easy one by a clever choice of coordinate directions.
 
  • #3
SammyS
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Homework Statement


2. Homework Equations [/B]

The Attempt at a Solution

[/B]
When I have to describe a motion i'm supposed to decompose a vector in two directions, for example in an inclined plane is decompose the weight in these directions: the normal to the plane and the parallel to the plane, and that seems logic, but could I decompose the weight in other directions? The same thing for the velocity in a parabolic motion, I decompose the velocity in the vertical and the horizontal directions because it is easier but could I describe the motion using other directions?for example the horizontal and another one inclined with the horizontal by an angle different of 90° ?

I think I could because it's a matter of choice, the motions doesn't change, changes just the way you look at it
In regard to your last question:
"... for example the horizontal and another one inclined with the horizontal by an angle different of 90° ?"​

You can decompose a vector into two components which are not mutually perpendicular. However, that tends to cause more problems than it solves..
 

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