# Mechanics - Vectors

> Source: https://ollybritton.com/notes/a-level/maths/topics/mechanics/vectors/ · Updated: 2020-09-22 · Tags: year-1, mechanics, school

##### What is $\hat{i}$??
The unit vector in the x direction.

##### What is $\hat{j}$??
The unit vector in the y direction.

##### What is the unit vector in the x direction??
$$
\hat{i}
$$

##### What is the unit vector in the y direction??
$$
\hat{j}
$$

##### What is $\begin{matrix}-2 \\ 3\end{matrix}$ in unit vector form??
$$
-2\hat{i} + 3 \hat{j}
$$

##### What is $4\hat{i} - 2\hat{j}$ in column vector form??
$$
\begin{matrix}4 \\ -2\end{matrix}
$$

##### What is the magnitude of displacement??
Distance.

##### What is the magnitude of velocity??
Speed.

##### What does $|v|$ mean??
The magnitude of $v$.

##### What is the notation for the magnitude of $v$??
$$
|v|
$$

##### Given two displacement vectors $a$ and $b$, how can you find their total distance??
$$
|a + b|
$$

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