physics help!! (vectors)

[alphatarget1]

consider the vector A=5i-3j Find:

a unit vector n1, parallel to( and pointing in the same diresction as) A. is your answer unique?

I don't get it, i looked up the answer and n1 = .86i-.51j and the answer is unique. how can it be unique?all i need is the same slope and the same direction and everything should be correct...

 

[dighn]

yeah it's unique. you can only change the direction and length of a vector, and if change direction, it's not pointing in the same direction anymore, and if you change the length from 1, it's nt a unit vector anymore

 

[alphatarget1]

ahhhh
should've paid attention in class. i have been having trouble doing that
unit vector=magnitude of 1, correct?

 

[dighn]

Originally posted by: alphatarget1
unit vector=magnitude of 1, correct?

yep

 

[alphatarget1]

so hmm... i tried to use the dot product equation and that didn't work very well... i'm not sure which equation i can use.

physics is a lot harder than i thought it would be :/

 

[Yossarian]

what's your vector Victor?

 

[Woodchuck2000]

Originally posted by: alphatarget1
consider the vector A=5i-3j Find:

a unit vector n1, parallel to( and pointing in the same diresction as) A. is your answer unique?

I don't get it, i looked up the answer and n1 = .86i-.51j and the answer is unique. how can it be unique?all i need is the same slope and the same direction and everything should be correct...

To find a unit vector in that direction, all you need to do is adjust the length so that it is equal to 1. The length of that vector is sqrt(34) units. To make the length 1, you simply divide both components by sqrt(34). It's unique because from the same origin, there is only one possible vector that is parallel and of unit magnitude.

 

[dighn]

Originally posted by: alphatarget1
so hmm... i tried to use the dot product equation and that didn't work very well... i'm not sure which equation i can use.

what do you mean