With your internet browser (Netscape or Internet Explorer) go to the CAPA home page at http://capa.colorado.edu/ or click on the link to the CAPA home page in your course Web page.

Select your course (phys1000, phys1010, phys1110, phys1120, phys2010, phys2020, etc.) from the menu.

Sign in with your student ID (9 digits, no spaces or dashes) and your 4-digit CAPA PIN (on your CAPA assignment).
"PIN" means personal identification number.

YOUR 4-digit CAPA PIN CHANGES EVERY WEEK.  Your 9-digit student ID is how CAPA knows who you are; your 4-digit CAPA PIN is how CAPA knows which homework set you are working on.

Select "Try current set".

Write your answers in the answer boxes, and press the "Submit all answers" button.  You may logon an unlimited number of times, and you may make submissions for a single problem at a time or for several problems at a time.  You use up tries only  for those problems which have answers typed in the answer boxes when you hit the "Submit all answers" button.

Important ! AVOID using the refresh/reload button of your Web browser (in the upper left corner)! When you hit reload/refresh, if there are any answers in your answer boxes, you use up one of your CAPA tries!

To enter answers with scientific notation, use the format 3.2E-8 (= 3.2 x 10^-8) or 5.5E+11 or 5.5E11 (=5.5x10¹¹). Use no spaces for scientific notation (NOT 3.2 E -8)

Enter numerical answers without commas. (Example: 342000 J, NOT 342,000 J)

For qualitative questions, the answer format is usually either "TTFT" (label each statement true or false) or "ACE" (pick each correct statement).  In general, no commas are used  in answers to qualitative questions. For such questions, read the directions very carefully to be sure you are entering answers in the correct format. CAPA is too dumb to recognize an incorrect answer format and will deduct tries if the answer format is not exactly correct.

Many answers require units. Use the standard SI abbreviations for units (N for newtons, kg for kilograms, s for seconds). Leave one space between the number and the units. Use * for multiply, / for divide, ^ = shift-6 for exponent.   Use these special symbols only when constructing units.  Examples: If answer is acceleration a = 4.53 m/s² , enter 4.53 m/s^2. The units of momentum are kg*m/s. You can group units with parentheses.  Example: J/(kg*K) means "joules per kilogram per degree Kelvin".

Always enter numerical answers as pure numbers, not expressions. For example, if the answer is 1/3, you must enter 0.333 or 0.3333, etc (NOT 1/3).  If CAPA sees any punctuation marks, * =asterisk, /=slash, ^=caret, _=underscore ,=comma, it will interpret these as an attempt to create a unit and will give the "incorrect units" warning.

In general, CAPA will accept an answer only  if it is within 1% of the exactly correct value.  ALWAYS maintain 3 sig.fig. precision in your calculations and enter the answer with 3 sig.figs. (or more) to ensure that your round-off error never exceeds 1%.  Do this even if the numbers in the question are given to only 2 sig.figs.  On some problems, particularly graphing problems, the error window is set  larger, 20% or more, so that high precision is not required.  Nevertheless, it is always wise to be as accurate as possible.

Occasionally, CAPA checks for sig.figs.  Usually 3 sig.figs. is OK. (On some questions, 2 or even 1 sig.figs. are OK, but it is safest to use 3 or more sig.figs. ). Don't enter an answer like "0.4". Enter it as "0.400" or "4.00E-2". CAPA thinks "200" has only 1 sig.fig. (pretty dumb!). To make CAPA understand, write it as 200.0 or 200. (notice the extra decimal point) or 2.00E2.

If CAPA thinks the units or the sig.figs. are wrong, it won't even look at your numerical answer. Do not interpret an "incorrect units" warning or an "adjust sig.figs." warning as an indication that the numerical answer is correct or incorrect. CAPA will not deduct a try if it thinks the units or the sig.figs. are wrong.

On some problems,  a hint is given after your first incorrect attempt. The same hint will always be given after an incorrect answer. So if the hint says "Use units of rad/s", understand that it will always say this even if your units are correct.