Question

LAB 1 PROBLEM 1: INTRODUCTION TO MEASUREMENT AND UNCERTAINTY

Welcome to 1101 Physics Laboratory! This lab exercise is meant to introduce you to measurement procedures, uncertainties in measurement, and the computer software that you will be using throughout the course. It will be worth your time to read through this entire lab and the next one as there are many helpful tips and references that you may want to use in later labs.

PART I—Measurement and Uncertainty

You perform quality control for BuggyMagic, the leading manufacturer of toy constant velocity buggies. Recently the company started manufacturing buggies at a second factory . Coincidently , the customer service department started fielding complaints at about the same time the new factory came on line. The customer service department couldn’t elaborate many specifics, only that many customers felt the buggies offered from the second factory were “inconsistent” and had “less magic” than the original buggies. The customer service manager at your company has decided that you need to check out the buggies ASAP.

You fly to the new factory with all sorts of sophisticated measurement and analysis equipment and a brand new buggy from the original factory, but sadly, when you arrive, all your luggage is lost by the airline. All you have is a smartphone (stopwatch) and a small flag affixed to a wooden dowel that is handed to you as you get off the airplane by a local welcoming committee. You’ll need to do your best assessing the buggies with what you have.

You have a stopwatch, wood dowel of fixed length and a toy buggy.

These are your first lab “Warm-ups”, to be done before the lab meets, written in your lab notebook, and turned into your TA as specified by the course syllabus. You may want to refer back to the appendices during the lab.

1) Read the appendix Significant Figures. Do the exercises at the end and write the results in your lab notebook under a section called “Warm-ups”.

2) Read the appendix Accuracy, Precision and Uncertainty and write the answers to the exercises in your lab notebook.

3) Read the appendix Review of Graphs.
4) Work out a plan as specified in the Prediction.

You should also start reading the appendix Video and Analysis. You will be using the software and equipment described at the very end of this lab more extensively later on.

EQUIPMENT

WARM UP

9

MEASUREMENT AND UNCERTAINTY

PREDICTION

With the limited tools on hand, what sorts of measurements can you make? Devise a plan to measure the dimensions and velocity of the buggies that you can compare to verify the ‘sameness’ of the buggies and later translate to metric units.

Answer 1

First, a station that includes feedback, with all the sophisticated electronics and simply lacking one mechanical button doesn't make sense, either to produce as a product or for agencies to stock spares for. You're probably talking about a part that wholesales for a couple of cents for a $400 station that's part of a S6000 system (and can cost well into five figures to retrofit an existing intersection) Second, if there was a station without a button, it would still look like it had a button, people would push at it and be confused when it doesn't move or do anything (if ped recall is enabled or the button has already been pushed the speaker says Wait", but it doesn't affect the cycle.) There's already a myth that pedestrian buttons don't "do anything" (that apparently started in New York when they converted from actuated controllers to fixed time and disconnected the buttons without removing them) The Econolite push-buttons, as used with the famous California neons, would turn a small red light to green to acknowledge that the button had been pushed. This was probably not more widespread due to the maintenance of the incandescent lamps, and has now finally been coming back with the new electronic buttons