There are a lot of instructions, etc.---they go on and on---it's just as bad for me---but as they used to say in the British Army, "It will all be right on the day."
I've tried to be as complete and concise as possible.
This page will probably get a bit modified or augmented before the lab final---but what is here now is probably all that is important.
Caption: Dr. Faustus calls up Mephistopheles in the play Doctor Faustus, 1604 (first performed before or circa 1592) by Christopher Marlowe (1564--1593).
The image is the woodcut frontispiece of the 1620 edition of Doctor Faustus, 1604.
The end of experimentation.
Credit/Permission: John (Iohn) Wright (c. 1580--1658), 1620 (uploaded to User:Pieter Kuiper, 2007) / Public domain.
Image linked to Wikipedia.
Sections
The lab counts for 20 % of the course---or so I vaguely recall.
But half the section performs starting at 5:30 pm sharp; the other at 7:00 pm sharp.
There will be a sign-up sheet for the start times.
Absolutely positively do NOT be late for your start time.
But if you are, we will fit you in somehow---do not despair.
If nothing else, you can start at 8:30 pm.
This is the advantage of being the last section of the day.
Bags, books, papers, old reports, your calculators, your cellphones, coats, hats, etc. must be left off to the side of the room.
Physics-department calculators will be provided:
These calculators will be available in the review session for practice.
Learn how to use them then.
There will be the appropriate calculator at each station.
The clock starts when everyone is at a station.
There are some deviations from that instruction sheet: e.g., there is some partial credit, but it is NOT given generously.
The marking instructions are to be tough---no gift marks for doing something meaningless.
There are two sets of stations: blue and pink.
Each set of stations is numbered 1 through 5.
If you start with a blue/pink station, you change to blue/pink stations only.
You go through the stations in order of their number.
For example, if you start at station 3, you go 3,4,5,1,2.
You NEVER return to a station.
You do not talk or interact with other students once the exam has started.
The lab final requires performance under pressure. Distractions must be minimized.
You can signal the instructor if some clarification is needed and you and the instructor can converse briefly in low voices.
He/she may be able to help you. It is a judgment call as to whether some point is something you should just know or whether some extra words can be spoken.
There are NO hints.
Occasionally, the instructor might have to help if their is an equipment malfunction of some kind.
Occasionally, help with the equipment may be needed.
For example, the ballistic pendulum (see below) can have a broken elastic band.
The question number is the same as the station number.
Each question is worth 5 marks.
The lab final is out of 25 altogether.
Fill in the answers in the blanks provided.
The questions have several parts: a, b, c, etc.
The difficulty level of the parts spans the range from easy to hard.
Yes, significant figures must be treated properly.
Yes, units must be given with answers.
Overall the questions are NOT hard. The difficulty lies in the short time available for each one and the pressure of the exam situation. The emphasis is performance, not pondering.
Preparation is the key.
Caption: The star of Charles Bronson (1921--2003) on the Hollywood Walk of Fame.
Image linked to Wikipedia.
Be as neat as you can be under the circumstances.
Erase or cross out anything WRONG that can confuse the marker about what you have done right.
You can use the back of the paper for scratch work.
NO other scratch paper is allowed.
You probably way off the true path if need extra scratch paper.
Try not to have any to-be-marked work on the back.
But if you must put to-be-marked work on the back, make sure that it is clear on the front that there is to-be-marked work on the back and on the back where this to-be-marked work is.
Skill in manipulating equipment and taking data is part of the test.
So good calculations are insufficient for full marks.
Calculations must be based on data taken.
There will be a 3-minute warning, then 1-minute warning, then move immediately.
So don't doddle on anything---get the data and calculations done in real time.
The questions CANNOT be that hard if you can take data do calculations in 15 minutes.
Try to minimize fumbling. But don't get rattled. Every new station is a new beginning.
Remember on any test first marks are usually easier to get than last marks. So get those first marks at each station for sure without worrying about ungot last marks from the last station.
If you get the work for a station done early, you can use the leftover time to review/complete earlier station work.
But you CANNOT return to a station as stated above. You have to use what data you have already.
There is NOT extra time after the last station 15-minute period.
The exam paper is handed in after the last station---with your card (see below).
Do NOT take equipment with you.
Do NOT trade it between stations.
Both sides of the card can be used.
There will be a supply of cards in the review session.
About the cards:
Review the relevant lab.
Make sure in the review session that you know how to do everything safely with the ballistic pendulum apparatus.
It takes some physical strength to load the spring. Make sure you get used to doing that.
We only load to the first catch remember.
Do NOT push back the spring without the ball in place. Without the ball, painful pinched fingers can result.
Remember the pendulum of the Ballistic pendulum will not stick at the upswing position.
Combing down the catches sometimes helps.
But you should be prepared to measure heights by eye on a upswing if the pendulum just won't stick.
You will have to plug in linear x-and-y data and get slope, intercept, and correlation coefficient.
At those stations requiring linear regression you will have Ti-83 Plus calculators.
Online procedure for performing this tricky feat are at Performing a Linear Regression on the TI-83+ or TI-84+. See also the video How to do linear regression on TI-83+ graphing calculator.
But it's useful skill to know how do it for yourself.
You never know when a klutzy instructor might NOT know how to do it.
The Ti-83 Plus calculators are finicky. If you don't do everything just right doing linear regression, everything goes bad. If you are super-experienced with the Ti-83 Plus calculators, maybe you can get back on track easily. If not, you may have to start over with whatever you want them to do.
Run through the procedure with the Ti-83 Plus calculator in hand over and over again until you get it.
Review the procedure immediately before the lab final.
Do NOT rely on your general calculator know-how. Calculators are all a bit different and under test conditions with NO hints from a written procedure, you probably will NOT be able just to find the procedure by playing around with Ti-83 Plus calculator.
The instructor will NOT give hints on calculator use during the lab final.
You can still get a slope and intercept by simple calculation:
slope = a = (y2-y1)/(x2-x1) , where (x1,y1) and (x2,y2) are the best data points in your estimate.
intercept = b = y1-a*x1 .
The correlation coefficient you cannot really estimate at all accurately by simple means.
Obtaining the slope and intercept by simple calculation may or may not be worth any marks.
It depends on how the marking scheme for the question is set.
Just in general on a test if one doesn't know what is exactly right try to fight out what must sort of right. It impresses the marker and builds confidence for the rest of the test.
You can work these out for yourself with the following formulae:
x_mean=(Σ_i x_i)/n
and
σ={[Σ_i (x_i-x_mean)**2]/(n-1)}**(1/2) ,
where x_i is the set of data points, n is the number of data points,
and Σ_i is sum on index i.
However, the supplied calculators can perform the calculations for you.
For a TI-30X a Solar, see the online instructions Quick Reference to Calculate the sample Mean, Variance, and Standard Deviation TI-30Xa (Texas Instruments).
For a Ti-83, Calculating Mean and Standard Deviation for a Sample with TI-83 which presumably will work for a Ti-83 Plus too.
See also the video COMPUTING SAMPLE STANDARD DEVIATION USING TI 83 PLUS---it's a bit longwinded.
Have the formulae above on your card and work mean and standard deviation out the hard way.
What if you have no time?
Eye-ball the data and estimate the mean and standard deviation.
If your estimates are good, the marker may never know that they were estimates.
For example, say you had data 3.2, 3.4, 3.5, 3.5, and 3.7.
Well 3.5 looks like a good significant-figure guess at the mean.
A rule of thumb (which often isn't bad) is that 2/3 of the input values should lie in the range (x_mean-σ) to (x_mean+σ) (Bev-308).
So I'd estimate σ = 0.1.
The actual values rounded-off to 1-decimal place are x_mean = 3.5 and σ = 0.2.
So the crude estimates are, respectively, not bad and not terrible.
For just glancing at the data, the crude estimates are fine.
You should be in the final 5th stage of learning to use a vernier scale---the stages are 1) incredulity, 2) denial, 3) bargaining, 4) grief, 5) acceptance.
There will be some changes.
But note 3 labs have been ruled (see just above).
Five labs are represented in the review-sessions stations.
At most there can be 2 done labs or variations on them that might be slotted in for the lab final.
You should figure out what they are and be prepped for them.
There may be a surprise---but the surprise could be that there is no surprise.
A version of the experiment itself is reported on the exemplary lab report posted on the metal cabinet. You should look that report over in the review session. It won't be there during the lab final.
Maybe.
You should be prepared to plot a graph.
If so, graphing paper will be provided.
Remember a graph should:
The validity of the exam as a fair test is at stake.
No one should have an unfair advantage.
This rule is in accordance with UNLV's ethics code and all academic ethics policy.
If you wish, you can go over the marked exam paper with the instructor.
You CANNOT make notes about what was on the exam during this postmortem.
If you find something marked wrong that was right---or vice versa---the mark will be changed.
But reweighing partially right answers is very unlikely---verging on impossible. A reasonable decision on the weighting of partially right answers was made to in the marking process and was adhered to as closely as possible for general fairness.
It is overwhelmingly better if mark changes are decided on before final grades are submitted to the registrar. Before, the change is simply in the hands of the instructor. After, the change usually requires some process.
The exam papers will eventually be shredded: usually by the end of the next semester.
Items for the lab final review session follow.
These are just for the lab course, NOT the lecture course.
Bring all your old reports to verify marks from.
You could review some of them beforehand: e.g., the ballistic pendulum since it will be on the exam (see below).
I will NOT run over everything discussed here.
These will much like what you will see on the lab final.
You CANNOT give hints on how to use them to the students during the lab final.
But you must be able to check that they work properly for your own self confidence in telling the students that calculators work fine and problems are due to their lack of preparation to use them.
Make sure each station has the equipment specified on the page at the back of the answer key.
Make sure the settings on the equipment that need settings are set right.
A trick is to use masking tape to tape things that should NOT be changed.
During the lab final, you should circulate from time to time and make sure the equipment is still in place and the setting are still set.
Students have a tendency to carry equipment and fiddle with settings.
Remember, they are under pressure.
For example, put weights back in their trays, unheap the equipment, take things off things.
At the time of station changes trying to make sure nothing is important is left pre-set by a departing student.
You shouldn't worry about this too much. There isn't much important to pre-set.
In any case, pre-setting probably can't help anyone. Students can't waste time trying to fathom what the last person did with the equipment---they have to set things right by their own knowledge.
Cellphones must be turned off.
Warn students no talking or interacting with each other.
Clarifications and occasionally help with equipment may require quiet conversion with the instructor.
Above all, students must be allowed to concentrate on what they are doing.
Get it back with their 3" x 5" card at the end of the exam session.
Have page with hand-in instructions: 1) card stapled to the front, 2) any graph stapled to the back.
You will have to race around to all the stations to clear the data before the students get to serious calculating.
For the TI-30Xa solars, this is easy. Just press on/AC to do the trick.
There will be at least two stations (one blue, one pink) and maybe more with Ti-83 Pluses. be cleared of data after every station period.
For the Ti-83 Pluses, clearing data is complicated. See:
If there is room for them, they can continue into the next session.
If not, they are out of luck.
Well ...