Question

Help please??? Find the velocity of vector v: v= (-12,9)

Answer 1

I don't get what you mean.

Answer 2

The magnitude of a vector <x,y> is sqrt(x^2+y^2).

Answer 3

yes but how do i find the velocity?

Answer 4

The velocity is completely defined by the given vector.
It could be that the speed (magnitude) is required, or that it needs the speed and direction.

Answer 5

The speed can be found by the method shown for magnitude above.
The direction would be by finding the angle (from the x-axis) using
theta = arctan(y/x)
if x is negative, add 180 degrees to the angle found.

Answer 6

im sorry...im confused :(

Answer 7

Velocity consists of the magnitude and direction.
It can be expressed as two components, as in <-12,9>.
Or it can be expressed as the speed (magnitude) and the direction.
For example, the velocity <7.071, 7.071>
is the same as a magnitude of 10 in the direction of 45 degrees.
The magnitude 10 is obtained by sqrt(7.071^2+7.071^2)=10, and the direction obtained by arctan(7.071/7.071)=arctan(1)=45 degrees.

Answer 8

I suppose you have done all this before in your physics class, or your math class on vectors.

Answer 9

okay so what would be the direction?

Answer 10

The direction would be calculated by
theta=arctan(y/x) where y and x are taken from the vector components.