# Math Help - vectors

1. ## vectors

I have some questions on a paper that I am typing up, and I've looked through my text book and I cannot find this, or I just don't know where to look.

-Explain how to write a vector in terms of it's magnitude and direction.

2. ## Magnitude and direction of a vector

Hello Chinnie15
Originally Posted by Chinnie15
I have some questions on a paper that I am typing up, and I've looked through my text book and I cannot find this, or I just don't know where to look.

-Explain how to write a vector in terms of it's magnitude and direction.
I'm not sure that there is any particular way to write a vector in terms of its magnitude and direction.

You can describe a vector in terms of its magnitude and direction by giving several examples; for instance:

1. The displacement vector of a point $B$ from a point $A$ can be written as $\vec{AB}$ and would be described in terms of the distance $AB$ (in suitable units) and the angle that the line segment $AB$ measured from a fixed direction. E.g. $AB = 5$ units in a direction making an angle of $30^o$ with the direction of the $x$-axis.

2. The velocity vector of a moving body can be described in terms of the speed of the body and the direction of its motion at a particular instant. E.g. a shell is fired in a north-easterly direction at $300$ m/sec at an angle of $45^o$ above the horizontal.
... and so on.