# need help understanding: if I have X then by superposition I can do X=x1+x2+x3+x4+x5+x6+x7+x8.....+xn

##### Full Member
Hi guys, sometimes I find it hard to go to aspect of "superposition" of something , I mean for example v1+v2+v3+v4 which they are speeds, I can say all of them are V=v1+v2+v3+v4 which V also speed.. but I can't imagine how superposition go.. can anyone help me how should I imagine the method of "superposition" to start using it in my solutions?! thanks alot.

#### HallsofIvy

##### Elite Member
I have no idea what "superposition" means here. Are these "v"s vectors and you are referring to vector addition?

• topsquark

##### Full Member
HI guys, sometimes I'm getting lost and don't know when I can use "superposition" rule.
for example if I have power F1 on specific item, and afterwards there's another power F2 in the same time work with F1 so we can solve the problem by taking F1 separately and doing calculation, afterwards taking F2 and doing calculations and then the solution is : first solution+second solution.

how's that correct? how can I know when I can use supervision between things and separate things from each other?!

thanks alot

#### Subhotosh Khan

##### Super Moderator
Staff member
HI guys, sometimes I'm getting lost and don't know when I can use "superposition" rule.
for example if I have power F1 on specific item, and afterwards there's another power F2 in the same time work with F1 so we can solve the problem by taking F1 separately and doing calculation, afterwards taking F2 and doing calculations and then the solution is : first solution+second solution.

how's that correct? how can I know when I can use supervision between things and separate things from each other?!

thanks alot
Please give us a "concrete" example.

In short - superposition is an "approximation" (all the answers from physical world are approximations).

When the relationship between the input & the output is linear - you can use superposition.

When the out-put is "small"- you can use superposition (very carefully).

• topsquark

#### tkhunny

##### Moderator
Staff member
Superposition = Making linear combinations of things

• topsquark