Calculator Tips/Statics

This page used to live at Calculator Tips but is now its own thing! This will be mostly useful for using a calculator to do work in a class needing vector math, specifically EGR 201 (Mechanics of Solids) which is sometimes called Statics.

Statics Functions

TI-83/84

Not as many built-in functions for vectors / matrices. See http://www.tc3.edu/instruct/sbrown/ti83/vecprod.htm for a program that will help with cross products.

TI-89

Vectors in General

Vectors may be entered surrounded by [ ]. That is, for some vector \(\vec{r}\):

\( \begin{align} \vec{r}&=r_x\hat{\imath}+r_y\hat{\jmath}+r_z\hat{k} \end{align} \)

say,

\( \begin{align} \vec{r}&=3\hat{\imath}-2\hat{\jmath}+6\hat{k} \end{align} \)

the TI version of the vector would be:

[3, -2, 6]

Note that the result will actually be surrounded by two sets of square brackets, representing a matrix. Be sure to use the unary negative operator (-) versus the binary subtraction operator - at the start of negative entries.

Dot and Cross Products

• Vector operations on TI Calculators: www.phys.lsu.edu/classes/spring2010/phys1100/TI_calc_vec.pdf

Unit Directions

• To find the unit direction for a vector, use
  • <2nd>--<5>MATH--<4>Matrix--L:Vector ops--<1>unitV()

Coordinate Angles

• To find the coordinate angles of a vector, you should first get the unit direction vector. Then, you must turn the unit direction vector into a list before taking the arccos of the list. Lists are surrounded by {} instead of []. To convert a vector to a list, use
  • <2nd>--<5>MATH--<3>List--F:mat->list()
    and put the desired matrix in as the argument; the result will be surrounded by {}. You can then apply the arccos to the list and get all three coordinate direction angles at once!