constant velocity tubes - equipment manualsphysics-astronomy-manuals.wwu.edu/pasco se-9076... ·...

© 1997 PASCO scientific $5.00

012-06697B

12/98

CONSTANT VELOCITY TUBES

Instruction Manual andExperiment Guide for thePASCO scientificModel SE-9076

IncludesTeacher's Notes

andTypical

Experiment Results

Phone (916) 786-3800 • FAX (916) 786-8905 • email: [email protected]

10101 Foothills Blvd. • P.O. Box 619011 • Roseville, CA 95678-9011 USA

better

teach science

ways to

Constant Velocity Tubes 012–06697B

The exclamation point within anequilateral triangle is intended to alert theuser of important operating and safetyinstructions that will help prevent damageto the equipment or injury to the user.

012–06697B Constant Velocity Tubes

Table of Contents

Section PageCopyright, Warranty, and Equipment Return............................................................................................ ii

Introduction.............................................................................................................................................1

Equipment...............................................................................................................................................1

Maintenance...........................................................................................................................................1

MSDS: CHEVRON Hydraulic Oil AW ISO 22......................................................................................2

First Aid Measures.................................................................................................................................2

MSDS: CITGO A/W Hydraulic Oil 46....................................................................................................3

Acute Exposure Symptoms.....................................................................................................................3

First Aid Measures.................................................................................................................................3

Pre-Lab Exercise: Graphing in the Lab............................................................................................... 4–8

ExperimentsExperiment 1: Constant Velocity Motion and the Linear Graph..........................................................9–13

Teacher's NotesPre-Lab Exercise...................................................................................................................................15

Experiment 1...................................................................................................................................16–17

Technical Support..................................................................................................................Back Cover

i


Equipment Return

Should the product have to be returned to PASCOscientific for any reason, notify PASCO scientific byletter, phone, or fax BEFORE returning the product.Upon notification, the return authorization andshipping instructions will be promptly issued.

➤ NOTE: NO EQUIPMENT WILL BEACCEPTED FOR RETURN WITHOUT ANAUTHORIZATION FROM PASCO.

When returning equipment for repair, the units mustbe packed properly. Carriers will not acceptresponsibility for damage caused by improperpacking. To be certain the unit will not be damagedin shipment, observe the following rules:

➀ The packing carton must be strong enough for the itemshipped.

➁ Make certain there are at least two inches of packingmaterial between any point on the apparatus and theinside walls of the carton.

➂ Make certain that the packing material cannot shift inthe box or become compressed, allowing theinstrument come in contact with the packing carton.

Address: PASCO scientific10101 Foothills Blvd.Roseville, CA 95747-7100

Phone: (916) 786-3800

FAX: (916) 786-3292

email: [email protected]

web: www.pasco.com

Copyright Notice

The PASCO scientific Constant Velocity Tubes (012-06697B) manual is copyrighted and all rightsreserved. However, permission is granted to non-profit educational institutions for reproduction of anypart of the manual providing the reproductions areused only for their laboratories and are not soldfor profit. Reproduction under any othercircumstances without the written consent of thecopyright holders is prohibited.

Limited Warranty

PASCO scientific warrants the product to be freefrom defects in materials and workmanship for aperiod of one year from the date of shipment to thecustomer. PASCO will repair or replace at its optionany partof the product which is deemed to be defective inmaterial or workmanship. The warranty does notcover damage to the product caused by abuse orimproper use. Determination of whether a productfailure is the result of a manufacturing defect orimproper use by the customer shall be made solely byPASCO scientific. Responsibility for the return ofequipment for warranty repair belongs to thecustomer. Equipment must be properly packed toprevent damage and shipped postage or freightprepaid. (Damage caused by improper packing of theequipment for return shipment will not be covered bythe warranty.) Shipping costs for returning theequipment after repair will be paid by PASCOscientific.

Copyright, Warr anty, and Equipment Return

Please—Feel free to duplicate this manualsubject to the copyright restrictions below.

CreditsAuthor: Jim HousleyEditor: Sunny Bishop

ii

1


IntroductionThe PASCO SE-9076 Constant Velocity Tubes are simple devices that students can useto generate velocity vs. time data for exercises to improve their graphing skills. Theplexiglass tubes contain colored, oil-based liquid of two different viscosities, and thereare three different lengths of liquid columns. A bubble of air trapped in each of the liquidcolumns rises at a constant velocity that is determined by the viscosity of the liquid.

EquipmentINCLUDED

• SE-9076 Constant Velocity Tubes (6)

ADDITIONAL EQUIPMENT REQUIRED

• Meter stick or metric ruler

• Clock with sweep second hand, or stopwatch

Maintenance• Clean with mild nonabrasive dish soap.

• Store in original box, out of direct sunlight.

Do not store in chemical storerooms.

• If a tube breaks, discard in accordance withyour school’s procedures for chemicalhandling.

➤ The fluids may cause stains on some materials.Stains may usually be removed by simpleprocedures such as the use of a laundry stainremover.

The red,orange and yellow tubes containCHEVRON Hydraulic Oil AW ISO 22. Thegreen, blue and violet tubes contain CITGO A/WHydraulic Oil 46. Please refer to the followingMSDS section for a short listing of exposureconcerns.

2


MSDS: CHEVRON Hydraulic Oil AW ISO 22To request a complete material safety data sheet (MSDS) you may either use the following contact information, usethe Chevron web site “www.chevron.com”, or request a copy directly from PASCO.

COMPANY IDENTIFICATION EMERGENCY TELEPHONE NUMBERSChevron USA Products Company HEALTH (24 hr): (800)231-0623 orEnvironmental, Safety, and Health (510)231-0623 (International)Room 2900 TRANSPORTATION (24 hr): CHEMTREC575 Market St. (800)424-9300 or (202)483-7616San Francisco, CA 94105-2856

PRODUCT INFORMATION: MSDS Requests: (800) 228-3500Environmental, Safety, & Health Info: (415) 894-1899Product Information: (800) 582-3835

FIRST AID MEASURESCHEVRON Hydraulic Oil AW ISO 22 is not expected to cause prolonged or significant eye irritation, or skin irritation,and is considered practically nontoxic to internal organs if swallowed. Prolonged or repeated breathing of petroleumoil mist can cause respiratory irritation.

EYE:

No first aid procedures are required. However, as a precaution flush eyes with fresh water for 15 minutes. Removecontact lenses if worn.

SKIN:

No first aid procedures are required. As a precaution, wash skin thoroughly with soap and water. Remove and washcontaminated clothing.

INGESTION:

If swallowed, telephone for medical advice. DO NOT make person vomit. If medical advice cannot be obtained, takethe person and product container to the nearest medical emergency treatment center or hospital.

INHALATION:

If respiratory discomfort or irritation occurs, move the person to fresh air. See a doctor if discomfort or irritationcontinues.

3


MSDS: CITGO A/W Hydraulic Oil 46To request a complete material safety data sheet (MSDS) you may either use the following contact information, orrequest a copy directly from PASCO.

COMPANY IDENTIFICATION EMERGENCY TELEPHONE NUMBERSCITGO Petroleum Corporation Technical Contact: (918) 495-5933P.O. Box 3758 Medical Emergency: (918) 495-4700Tulsa, Oklahoma 74102 CHEMTREC Emergency: (800) 424-9300

ACUTE EXPOSURE SYMPTOMSCITGO A/W Hydraulic Oil 46 is generally of a low order of toxicity.

EYE:

This material may cause transient eye irritation.

SKIN:

This material may cause transient skin irritation.

INGESTION:

If swallowed, there is slight risk of aspiration to the lungs. Upon ingestion, gastrointestinal discomfort, diarrhea, andheadache may occur.

INHALATION:

In enclosed spaces or when hot, vapors may reach concentrations sufficient to cause drowsiness, dizziness, headaches,nausea, or lung irritation. Elevated mist concentration well above applicable workplace exposure levels may causesevere lung damage.

FIRST AID MEASURESEYE:

Flush eyes with large volumes of fresh water. Seek medical attention if pain, excessive tearing or irritation persists.

SKIN:

Wash exposed skin with soap and water. Remove contaminated clothing. Launder before use. Seek medical attentionif tissue damage occurs or if irritation persists.

INGESTION:

Induce vomiting ONLY upon the advice of a physician. Seek medical attention immediately.

INHALATION:

Move victim to fresh air. If victim is not breathing, immediately begin cardiopulmonary resuscitation (CPR). Ifbreathing is difficult, 100 percent humidified oxygen should be given by a qualified individual. Seek medical attentionimmediately.

4


Pre-Lab Exercise: Graphing in the Lab

Purpose

To help students develop graphing skills that will be needed to complete the activitieswith the Constant Velocity Tubes

Background

Graphs are an effective way of presenting numerical data in a laboratory report, but thatis not their only use. Graphs can also be used to determine the mathematical relationshipbetween two variables. In the following graphing exercise, you will work with twotypes of variables: an independent variable and a dependent variable. An independentvariable is the part of the experiment that you change in a measured, controlled way.The dependent variable is the part of the experiment that changes as a result of thechanges in the independent variable.

This exercise will help you develop the graphing skills you will need in your experimentswith the Constant Velocity Tubes. You will draw a graph of experimental data that werepreviously collected.

In a previously conducted experiment, a measured volume of liquid mercury(independent variable) was added to a glass beaker, and then the mass of the beaker andmercury (dependent variable) was determined with a platform balance.

Procedure

1. In an experiment, there are generally several variables that might possibly affectthe dependent variable. If we can arrange to allow only one of these to vary andhold the others constant during the experiment, it is far easier to interpret the results.Besides the volume of liquid, the kind of liquid is an example of a variable whichmight possibly affect the mass reading; thus the kind of liquid used should not bechanged during the experiment. Can you think of any other variables that shouldbe held constant in this experiment?

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

2. For the first data point of this experiment, the beaker was filled to the 250 ml markwith liquid mercury, and the mass reading from the pan balance was 3,600 g. Next,the beaker was emptied and then filled to the 50 ml mark. The mass reading wasthen 1000 g. Notice that these first two sets of data represent two extremepossibilities. Why do you suppose such values were chosen?

________________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________________________________________________________________________________________________________

5


3. It is useful to sketch a graph of the data as it is collected and examine the pattern as it forms.Make a graph on the grid below using the data above, as follows:

a) Label the horizontal axis with the name of the independent variable (sometimescalled the “control” variable). Follow the name with the type of units ofmeasurement being used in parentheses ( ). In a similar manner, label the verticalaxis, which is used for the dependent variable.

b) Number the axes. Start numbering with zero at the origin (lower left corner).

➤ When numbering the axes, number the lines, not the spaces. Choose aregular numbering system (e.g. by fives, tens, fifties, etc). Adopt a spacingsystem that numbers every second, every fifth, or possibly every tenth line.These choices make it easier to locate and plot data from metric systemmeasurements, as compared to systems involving numbering every three orfour lines. The numbering system chosen will depend on the largestnumbers that will need to be plotted.

c) Plot the data points. Make small, precise points. Then, because small points are hardto find, make them more obvious by surrounding each point with a small circle,triangle, or similar figure. These are called point protectors.

➤ If you feel uncertain about your work thus far, you should seek helpbefore proceeding.

➤ Drawing a graph as an experiment proceeds can help you to decide whatto do next. The two points plotted are just the beginning of a pattern.Obtaining and plotting additional data points makes the pattern becomeclearer.

6


4. On the same graph, plot this additional data:

150 ml — 2,500 g and 100 ml — 1,600 g

5. Looking at your graph, what volume would you suggest be used next?________________

6. Now plot this data pair: 200 ml — 1,300 g

➤ Plotting data on a graph helps reveal mistakes. If the graph ismade as the experiment is being done, the mistake can be corrected.Later, it may be difficult or impossible to reconstruct the experimentand correct the error.

7. Which of the data points on your graph represents a mistake? __________________

➤ It is not wise to immediately discard data that “looks wrong”.Many important new discoveries in science “looked wrong” at first.In this case, however, a simple mistake was made: the “1” and the“3” in the last mass reading were transposed. The data pair shouldhave been: 200 ml — 3,100 g.

8. Correct the mistake noted.

9. By now a pattern should be clear. To make the pattern more visible, draw a best-fitline (the line that most closely follows the pattern revealed by the data points).Since the pattern seems to be straight, it is appropriate to use a straight edge to drawthe line. (A transparent plastic straight edge is particularly useful for this purpose.)Extend the line all the way to the vertical axis.

➤ You may find that the points don’t quite fit on the line. This isbecause all of our data include uncertainty. The uncertainty is dueto imperfections in the measuring tools, our inability to read thesetools perfectly, and perhaps the fact that other variables have varieddespite our attempts to keep them constant. The odds are that someof the points are too high, and some are too low. Even though theuncertainty in the data makes the locations of the data points slightlyin error, we can discover the pattern that represents the truerelationship between mass and volume. We assume that the truth isthat the pattern is a straight line, and that the points miss the line dueto errors.

➤ Computer programs, including built-in programs in some calcu-lators and Science Workshop® can also draw a best-fit line. Theprocess is called curve-fitting. If we decide in advance that a straightline is the appropriate pattern, the process is called linearregression.

7


➤ In algebra, a graph of this type is described by the equation y = mx + b, where:

y is the quantity on the vertical axis,

x is the quantity on the horizontal axis,

m is the slope, and

b is the y-intercept (also called the vertical intercept).

By replacing each of these abstract symbols with the actual items dealt with in theexperiment, the mathematical equation can be transformed into a physics equation.

10. In the space below write the equation that results when you replace the symbols y and xwith the actual physical units, mass and volume in the equation for a straight line, y = mx + b:

11. In the space below, substitute y-intercept value (360 grams) for b in the equation (noticethat the dimensional units grams are part of the value):

12. It is unlikely that your graph shows a y-intercept of exactly 360 g. What is the value of they-intercept, according to your graph?

13. Calculate the slope, m, as follows:

The slope, m, is found from the formula slope = rise / run. The first step in finding slopeis to mark two points directly on your best-fit line. Label these points so they won’t beconfused with data points. The farther apart you place them, the more accurate your resultwill be. Choosing points that are on one of the grid lines will also improve your accuracy.

a) Select two points on the best-fit line, and read their coordinates from your graph:

First Point: y1-coordinate_____________ x

1-coordinate______________

Second Point: y2-coordinate_____________ x

2-coordinate______________

Did you remember to record the units of measurement, as well as the number?

b) Calculate the rise and run from these coordinates.

rise (y2 - y

1) = __________________ run (x

2 - x

1)= __________________

Did you remember to record the units of measurement, as well as the number?

8


c) Now calculate the slope (don’t forget the units):

➤ Your answer should be approximately 13.4 g/ml. You should notexpect to get exactly this answer.

d) Now substitute this value for slope (m) in the formula:

➤ This equation allows us to calculate the mass reading that would resultif some other volume of mercury were tried. Using algebra to solve forvolume, we can also obtain an equation that tells us what volume of mercuryto use to cause some particular mass reading.

14. Solve the equation for volume. Ask for help if you need it.

➤ The original equation would be much more useful if it could apply toother substances besides mercury as well as containers other than the onethat was used in this experiment. Often, reasoning allows us to adapt anequation to other purposes.

15. Look at your graph and see if you can express in words the meaning of the y-intercept. (Notthe mathematical meaning, but rather some aspect of the experiment that this value represents.Hint: What is the volume, at the y-intercept?)

_________________________________________________________________________________

16. Does the value of the slope remind you of anything? How about the units? Hint: use areference to look up the physical properties of mercury. Keep in mind that the numericalvalue we obtained by experiment will not be exact.

_________________________________________________________________________________

17. Finally, the mass reading from the pan balance might better be called gross mass, which isthe mass of both the container and the contents. The preceding ideas can be used to rewritethe equation into a more generally useful form:

Gross Mass = Density of Contents * Volume of Contents + Mass of Container

slope = riserun =

y2 – y1

x2 – x1=

9


Experiment 1: Constant Velocity Motion and the Linear Graph

Purpose

The purpose of this experiment is to study a rising bubble and to develop a quantitative descriptionof its motion.

Theory

Under a given set of conditions, the motion of a rising bubble is highly repeatable. At the mostbasic level, describing motion involves describing position as a function of time. In thisexperiment, variables that might conceivably affect the bubble’s motion, such as tube angleand temperature, are held constant. Position data are recorded for a variety of times.

Before position data can been meaningful, a reference frame must be defined. For convenience,the initial position of a moving object is often chosen to be zero. Since the initial position of thebubble is concealed in this experiment, it is not possible to determine the initial position.Instead, the end of a tube is defined as position zero, simply because this is a convenient placeto measure from. Given that the bubble moves upward, it is most convenient to define positionsabove the end of the tube to be positive.

When the position–time data points from one of the tubes are graphed, a clear pattern to thedata can be clearly seen. Plotting data from other tubes on the same graph produces similarpatterns, but with distinctive differences that may be related to the differences in the motion.The patterns that emerge are of a type familiar to algebra students, and an equation for each canreadily be written.

Procedure

➤ Follow your lab’s safety procedures, including wear-ing safety glasses.

1. Obtain a tube which has one end wrapped in paper. Do not removethe paper. Record the color of the fluid in the tube.

_____________________

2. Work with a partner to practice timing the motion of the bubble asfollows:

a) Hold the tubing nearly horizontal, but with the wrappedend slightly higher. Allow time for the bubble to travel asfar as it can under the paper wrapping (Figure 1) .

b) Your partner should be watching the clock (or operatingthe stopwatch). Choose a time interval that is long

Figure 1

wrappedend

10


enough for the bubble to come into view, but short enough so that the bubble doesnot reach the top of the tube. At a convenienttime your partner should say “start.”

c) Quickly rotate the tube into a verticalposition; the wrapped end should bedownward (Figure 2).

d) As a bubble comes into view, keep the indexfinger of one hand pointing at the bottom ofthe bubble as it rises. When your partner says“Stop,” stop moving your finger and hold itthere to mark the position of the bottom of thebubble (Figure 3).

e) Measure the distance from the bottom of thetube to the point marked by your finger(Figure 4).

f) Record the time of travel and the bubble’sposition and plot the point on the graph.

3. Do the above for two different time intervals. Chooseone time interval that is short enough so that thebottom of the bubble has just emerged from the paperwrapping. Choose another time interval almost longenough to permit the bubble to reach the top of the tube. Enter your data into the data table.

wrappedend

Figure 2

Figure 3

Figure 4

4. Prepare a graph, and plot the two data points.

When your partner saystime, mark the position ofthe bottom of the bubblewith your finger. Measure the

distance (d ) fromyour finger to thebottom of thetube.

d

11


5. Choose other lengths of time between these two extremes. Enter the data into the datatable. Plot the points as you go and examine the pattern as it forms. Choose additionaltimes to try based on missing parts of the pattern. Be on the lookout for obvious mistakes asyou plot the points. Do not rush to throw out any of your data, though.

6. Draw a best-fit line though your data. A straight line drawn with a ruler should do a goodjob of representing the pattern of the data. If it does not, ask your instructor for advice.

➤ If time permits, improved accuracy can be obtained by repeating a timemore than once and plotting the average position for that length of time.

7. If necessary, extend your line until it meets the vertical axis. What is the value of the y-intercept? ___________________ (Don’t forget units of measurement.)

8. What is the meaning of the y-intercept? (Not the mathematical meaning, but the meaningin terms of the details of this experiment.)

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

9. Unwrap the paper from the tube and examine the tube. Measure from the bottom of thetube to the place where the bottom of the bubble started. (If the bubble started somewhereunder the black end cap, you may estimate its starting position at 1 cm.) Record thismeasurement: ____________________

Replace the wrapping.

10. Compare your results for steps 7 and 9 above and comment:

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

11. Some of the tubes in the set have bubbles that travel at essentially the same speed as the oneyou just worked with. Others travel at a dramatically different speed. Choose a tube of adifferent color, but with a speed that is essentially the same as the one you used before.Take time and position data for this tube, and enter it into a new data table, but plot thepoints on the same graph you used before. Draw a best-fit line for this data, too.

12. Compare the best-fit lines from the two tubes for similarities and differences. Try to explainthe reasons for them. Unwrap the paper from the second tube to verify your explanation.Replace the wrapping.

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

12


13. Select a tube with a bubble that travels at a distinctly different speed. In this tube, does thebubble move faster or slower than the previous two you tried?_______________ Takeposition–time data for this tube and enter it into a new data table, but plot the points on thesame graph you used before. Draw a best-fit line for this data, too.

14. Compare this line to the other two lines. Try to explain the reasons for any similarities ordifferences, including the different slope. Unwrap the paper from this third tube to verifyyour explanation. Replace the wrapping.

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

_______________________________________________________________________________________________

➤ The remainder of the analysis may be performed outside the lab.

15. For each of the three tubes you experimented with, calculate the slope of the best-fit line.Fill in the blanks showing the results of your intermediate steps, as well. Don’t forget toinclude units of measurement.

Color of tube:__________

First Point: y-coordinate _____________x-coordinate ______________

Second Point: y-coordinate _____________x-coordinate ______________

rise = __________________ run = ______________

slope = ______________________



Second Point: y-coordinate _____________x-coordinate ______________

rise = __________________ run = _____________

slope = ______________________



Second Point: y-coordinate _____________ x-coordinate ______________

rise = __________________ run = ______________

slope = ______________________

13


16. What arguments can you offer, based on this experiment, that the speed of the bubble is thesame as the slope of the position vs. time graph?

_____________________________________________________________________________________________________________________________________________________________________________________________

___________________________________________________________________

In algebra, a graph of the type seen in this experiment is described by the equation:

y = mx + b

where: y is the quantity on the vertical axis,

x is the quantity on the horizontal axis,

m is the slope, and

b is the y-intercept (also called the vertical intercept).

17. Write equations for each of the three tubes you experimented with by substituting into thebasic equation above the appropriate values for slope and y-intercept, as well as the namesof the variables that x and y represent.

Color:_________ Equation: ________________________________________

Color:_________ Equation: ________________________________________

Color:_________ Equation: ________________________________________

18. By replacing each of these abstract symbols with the actual items dealt with in the experiment,the mathematical equation can be transformed into a basic equation of motion. Write abasic equation for motion using the words position, time, velocity, and initial position.

______________________________________________________________________________________________________________________________________________________________________________________________

_______________________________________________________________________________________________

14


Time (s) Position (cm)

Data Tables and Graph

Time (s) Position (cm)

15


Pre-lab Exercise

Answers to questions

1. Other potential variables that should be held constant include the container (could be adifferent mass), the pan balance used (might not be properly calibrated, or calibration methodscould be crude), two different methods of measuring the liquid (eg beaker vs. graduatedcylinder), or ambient temperature.

2. Plotting the extremes allows one to begin the graphing process with the assurance that alldata will fit on the graph and to more accurately guess the slope of the true line that representsthe relationship between the variables (assuming it is a linear relationship).

5. Answers will vary.

7. the 200 ml, 1300 g point

10. mass = m • volume + b

11. mass = m • volume + 360 g

12. Answers will vary around 360 g.

13. a) y1 = 1640 g x

1 = 100 ml

y2 = 3675 g x

2 = 250 ml

(Answers will vary somewhat.)

b) y2 - y

1 = 2035 g

x

2 - x

1 = 150 ml

(Answers will vary somewhat.)

c) 13.6 g/ml(Answers will vary somewhat.)

d) mass (g) = 13.6 g/ml • volume (ml) + 360 g

14.

15. The y-intercept equals the mass of the beaker.

16. The slope represents the density of the liquid mercury. The accepted value for the densityof mercury is 13.5 g/ml (room temperature) or 13.6 g/ml at 0 °C.

volume (ml)

50 100 150 200 250

1000

2000

3000

4000

mas

s (g

)

Teacher’s Notes

volume (ml) =mass (g) – 360 g

13.6g/ml

Graph of Plotted Data

best-fit line

correcteddata point

mistakendata point

16


Experiment 1

➤ To preserve the �discovery� aspect of the lab, you will need to coverthe ends of the tubes with paper before the lab starts. A sheet of notebookpaper secured with rubber bands and masking tape works well. Scotch (orcellophane) tape is very difficult to remove from the tubes.

7. Red or violet tube: 1 cmOrange or blue tube: 9 cmYellow or green tube: 16 cm

8. The y-intercept is the position of the bubble at time = 0; more simply, it is the initialposition of the bubble.

9. The measurement should be approximately the same value as the value at the y-intercept.

10. The answers to 7 and 9 should be approximately the same.

11.

12. The result should be two parallel lines having the same slope but different y-intercepts.The difference in y-intercepts is due to the different initial positions.

13. See graph above.

2 4 6 8 10 12 14 16 18

10

20

30

40

50

60

70

80

ELAPSED TIME (SECONDS)

17


14. A greater slope corresponds to a greater speed.

15. The slopes (speeds) will vary depending on room temperature. Typical values might be:red, orange, yellow tubes: 5.4 cm/sgreen, blue, violet tubes: 3.8 cm/s

16. a) Greater slope corresponds to greater speed.

b) The dimensional units of the slope are appropriate for speed (velocity).

c) The rise is the change in position during a time interval, and the run is the elapsedtime during that time interval. Rise divided by run equals the average speed(velocity).

17. for example, green: position = 3.8 cm/s • time + 16 cm

18. position = velocity • time + initial position

18


Technical Support

Feedback

If you have any comments about the product or manual,please let us know. If you have any suggestions onalternate experiments or find a problem in the manual,please tell us. PASCO appreciates any customerfeedback. Your input helps us evaluate and improve ourproduct.

To Reach PASCO

For technical support, call us at 1-800-772-8700(toll-free within the U.S.) or (916) 786-3800.

fax: (916) 786-3292

e-mail: [email protected]

web: www.pasco.com

Contacting Technical Support

Before you call the PASCO Technical Support staff, itwould be helpful to prepare the following information:

➤ If your problem is with the PASCO apparatus, note:

- Title and model number (usually listed on thelabel);

- Approximate age of apparatus;

- A detailed description of the problem/sequence ofevents (in case you can’t call PASCO right away, youwon’t lose valuable data);

- If possible, have the apparatus within reach whencalling to facilitate description of individual parts.

➤ If your problem relates to the instruction manual,note:

- Part number and revision (listed by month and yearon the front cover);

- Have the manual at hand to discuss yourquestions.

constant velocity tubes - equipment manualsphysics-astronomy-manuals.wwu.edu/pasco se-9076... ·...

Documents