# Resolution of Vecotrs

#### sArGe99

1. The problem statement, all variables and given/known data
I just wanna get my concepts right again. How many times can a vector be resolved into horizontal and vertical components? In the case of a mass placed on a wedge, the weight of the body can be resolved into mg sin (angle) and mg cos(angle). Can this mg sin(angle) be further resolved and resolved again... Surely it would have components in every direction, then?

2. Relevant equations

Resolution using sine and cosine functions

3. The attempt at a solution
Again, none of the books really helped me on this

#### LowlyPion

Homework Helper
1. The problem statement, all variables and given/known data
I just wanna get my concepts right again. How many times can a vector be resolved into horizontal and vertical components? In the case of a mass placed on a wedge, the weight of the body can be resolved into mg sin (angle) and mg cos(angle). Can this mg sin(angle) be further resolved and resolved again... Surely it would have components in every direction, then?

2. Relevant equations

Resolution using sine and cosine functions

3. The attempt at a solution
Again, none of the books really helped me on this
Typically you want to choose a useful axis set. Gravity direction usually makes a fine choice and ⊥ planes make up useful 2nd and 3rd dimensions.

But generally you don't make a lot of different projections of things that are already projections since the original forces can be projected in whatever angles you need directly.

#### sArGe99

But in cases, like the one with an inclined plane the angle of inclination is given, it cannot be changed - say its theta. If we want the projection to be in other directions than what is given by sine and cosine components of theta, what do we do?
For example, mg sin theta acts parallel to the wedge surface and cosine component perpendicular. But what if we need a component parallel to the horizontal?

#### LowlyPion

Homework Helper
But in cases, like the one with an inclined plane the angle of inclination is given, it cannot be changed - say its theta. If we want the projection to be in other directions than what is given by sine and cosine components of theta, what do we do?
For example, mg sin theta acts parallel to the wedge surface and cosine component perpendicular. But what if we need a component parallel to the horizontal?
I look to the original force wherever possible. Why take sines of cosines if you don't have to?

### The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving