Physics Laboratory Handbook PDF

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FACULTY OF SCIENCE AND INFORMATION TECHNOLOGY SCHOOL OF MATHEMATICAL AND PHYSICAL SCIENCES

PHYS1210 ADVANCED PHYSICS Semester 1, 2016

LABORATORY WORKBOOK Name: Student Number: Laboratory Day & Time:

SAFETY INDUCTION COMPLETED



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RECORD OF STUDENT MARKS

Student Name: Student Number: Laboratory Day & Time: Laboratory Team (Letter): Laboratory Partners:

Date

Experiment Name

Workbook (W)

Report (R)

Lab Mark (2W+R)

Why are Experimental Uncertainties Important?

/20

/20

/60

How Old is the Universe?

/20

/20

/60

Designing a Roller Coaster

/20

/20

/60

What happens in a collision?

/20

/20

/60

The Heat Engine

/20

/20

/60

Radiation and Shielding

/20

/20

/60

Resonances and the Speed of Sound

/20

/20

/60

Additional Notes (staff only)

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Demonstrator Signature

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WELCOME TO THE FIRST YEAR PHYSICS LABORATORY During the physics laboratories you will be conducting experiments that will help you understand some of the fundamental physics concepts covered in this course. You will also develop skills in laboratory techniques, performing calculations, recording information, graphing and the treatment of experimental uncertainties. This workbook will provide instructions on how to undertake the experiments and it will be where you record your laboratory work. CONTENTS Organisation of the Laboratory

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Missed Laboratories

9

Code of Conduct

11

Laboratory Marking

13

Laboratory Safety

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Experiments Why are Experimental Uncertainties Important?

23

How Old is the Universe?

35

Designing a Roller Coaster

49

What Happens in a Collision?

63

The Heat Engine

77

Radiation and Shielding

89

Resonances and the Speed of Sound

105

Appendix 1: Significant Figures

117

Appendix 2: SI Units

118

Appendix 3: Graphing Techniques

119

Appendix 4: Propagation of Uncertainties

126

Appendix 5: Guide to Writing Scientific Reports

129

Appendix 6: Sample Laboratory Report

132

Appendix 7: Values of Physical Constants

134

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ORGANISATION OF THE LABORATORY Location The laboratories are held in either SB308 or SB309 on Level 3 of the Science building (SB). Timetable You will have registered for a particular laboratory session as part of the online course enrolment process. You must attend the session in which you are enrolled. Variations are only permitted where prior approval has been granted. If you have received approval to attend an alternate session, you must bring a copy of the approval email to the session. If a laboratory class falls on a public holiday, it will usually be rescheduled. A detailed timetable showing which experiments are to be conducted each week and any variations due to holidays will be posted on Blackboard at the start of semester. People in the Laboratory The Laboratory Coordinator is responsible for all academic issues including comments, questions and problems you and staff may have regarding the laboratory work. Assoc. Prof. Vicki Keast Room P115 Phone 4921 5447 Email [email protected] The Laboratory Manager is responsible for the day-to-day operation of the laboratory. They organise student rosters, staffing, recording of marks, equipment and other issues related to the organisation of the laboratory. Mr. Mark Hopkins Room SB311 Phone 4921 6169 Email [email protected] There will be approximately one Laboratory Demonstrator per 12 - 15 students in each laboratory session. They will assist you to complete your experimental work in the correct manner and help you understand the physics behind the experiments. They are responsible for marking your experimental work and report. One of these demonstrators will be designated as the Laboratory Supervisor and they are responsible for the running of the session. The Physics Admin Officer assists with some of the administration matters of the laboratories. They can help with some timetabling issues (before Week 2). Laboratory Exemption Forms and Missed Assessment Forms are submitted to them. Mrs Cheryl James Room P106 Phone 4921 5513 Email [email protected] Use of Email You must use your university email for any correspondence with members of staff about the physics laboratories. For security and privacy reasons, non-university emails addresses are not appropriate. Please also ensure that the course code is included in your email, as well as sufficient detail for the person receiving it to understand and act on your query. Student Laboratory Teams The laboratory work is conducted in teams of three students. Near the start of semester you will be assigned laboratory partners according to a roster which will be posted on Blackboard. Partners must not be changed from those rostered and people without a partner must not join other teams without permission from the Laboratory Supervisor.

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Materials Required You should purchase this laboratory workbook and bring it along to the first laboratory (in Week 3). It will remain in the laboratory until all the laboratory exercises have been completed and marked. After this, you will be able to collect the workbook to assist in your studies for the final exam. You will need to bring pens, pencils, a ruler and a calculator to each laboratory session. You will need to bring the relevant lecture notes and the textbook to the laboratory. Most laboratories will start with a theoretical review, where you will need to access these references. You may wish to bring some study notes from your preparatory reading. Suggested readings for each laboratory will be made available on Blackboard. You must not bring any previously completed student workbooks. Laboratory Equipment The apparatus required will be set out on the bench. If you feel that there is insufficient equipment to perform the experiment, consult the demonstrator. On no account must the apparatus on other benches be removed or interfered with. Faults or damage to apparatus are to be reported to the laboratory supervisor, a demonstrator or to the laboratory manager. On completion of experimental work, students are to dismantle the apparatus assembled during the course of the experiment, disconnect any electrical circuits and leave the apparatus as found and ready for the next group of students. Although many experiments have detailed step-by-step instructions, students are expected and encouraged to make any additional measurements which they consider will contribute to their understanding of the physical situation. Any such additional measurements must be discussed first with a demonstrator. Punctuality You must arrive on time. Important information about the laboratory is provided at the start of class. This may include essential safety information. If you arrive more than 20 minutes late, you may be refused entry to the laboratory and, as a consequence, receive a mark of zero for the laboratory. Signing in and out of the Laboratory There is an attendance sheet at the entrance to the laboratory. You must sign in when you enter the laboratory and sign out when you leave, noting the time. This is required for safety reasons as the information is of critical importance in the event of an emergency situation. Disabled persons Let the Laboratory Coordinator know if you need assistance. You should also contact the Disability Support Service on 4921 5766 or email [email protected]. This service assists with liaison with university staff and community agencies, with special facilities for examinations, and with class support. The service is completely confidential. Language University policy is that all classes are conducted in English and no special consideration is given for unfamiliarity with English. However, if you have difficulties with English, the Language Centre and International Student Support Unit provide free continuing English assistance for university students. 8

MISSED LABORATORIES You must attend and complete all laboratories. If you do not attend a laboratory, you will receive a mark of zero for that laboratory. There is no minimum requirement for attendance at the laboratories. However, if you miss laboratories it is likely that you will fail or perform poorly in the course overall. Under some circumstances it may be possible for a catch-up laboratory to be arranged. The allowable circumstances for which a catch-up laboratory will be granted are those covered under the Adverse Circumstances Policy. See http://www.newcastle.edu.au/policy/000939.html According to the policy, the allowable circumstances are: • health grounds – either physical or psychological; • compassionate grounds (e.g. the death or serious injury of a close family member or friend); • hardship (e.g. sudden loss of employment; family breakdown; or severe disruption to domestic arrangements); • trauma (e.g. impact of crime or accident; impact of natural disasters); • unavoidable commitments (caring responsibilities, cultural or religious commitments; commitments within the Australian Defence Forces or similar international bodies; commitments as an elite athlete to attend an event; obligations to jury duty or another commitment that cannot by their nature be rescheduled).

WHEN YOU MISS A LABORATORY YOU MUST: 1. Complete a “Missed Assessment Form”. These are available on Blackboard or outside the Physics Office (P106). 2. Attach supporting documentation to your request. Requests without supporting documentation will be denied. A medical certificate must be provided for missed laboratories due to illness. 3. Submit your request within 3 calendar days of the missed laboratory. This can be done in person or via email to the Physics Admin Officer (P106).

If you know ahead of time that you will need to miss a laboratory, for an allowable reason, then you must submit the Missed Assessment Form and supporting documentation in advance, so that alternative arrangements can be made. Requests submitted after a missed laboratory, for a reason that could have been predicted beforehand, may be denied. If your request for a catch-up laboratory is approved, you will receive an email with details of the alternative laboratory session. If you do not respond to this email in a timely manner, the approval for a catch-up laboratory may be revoked.

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FIRST YEAR PHYSICS LABORATORIES CODE OF CONDUCT

In participating in the first year physics laboratories, I agree to: − Be punctual in attendance. − Behave in a respectful manner to all other people in the laboratory. − Take responsibility for my own learning. − Actively support the learning of the other students in my laboratory team. − Contribute equally to the work of my laboratory team. − Conduct my laboratory work with honesty and scientific integrity. − Not provide details about the laboratory work to other students if doing so would give them an unfair advantage. − Not seek details about the laboratory work from other students if doing so would give me an unfair advantage.

Signed: ………………………………………………….. Date:………………………. Full Name:……………………………………………………………… Student Number: …………………………………………………………

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LABORATORY MARKING •

A record of all experimental work is to be written BY EACH STUDENT IN THEIR OWN WORDS in the spaces provided in this LABORATORY WORKBOOK.

•

The experimental work recorded in the Laboratory Workbook will be given a mark out of 20 according to the assessment criteria provided.

•

After completion of the experimental work an additional 2-3 page “LABORATORY REPORT” must be completed. This report summarised the main aims and outcomes of the experiment. Blank pages are provided in the workbook in which to write the report. EACH STUDENT WRITES THEIR OWN REPORT.

•

The Laboratory Report will be given a mark out of 20 according to the assessment criteria provided. Further guidelines for writing laboratory reports are also provided in Appendix 5. A sample report is provided in Appendix 6.

•

Your Final Mark for the experiment will be a combination of the Workbook Mark and Report Mark according to the following formula: Final Mark (out of 60) = 2 × Workbook Mark + Report Mark

•

All experiments contribute equally to your final laboratory mark.

•

The entire laboratory work must be completed during the 3 hours of the laboratory session. Your Laboratory Workbook with Report is to be handed to your demonstrator before you leave the laboratory. You cannot complete them at home

•

Work must be written in blue or black ink (not pencil). You should use pencil for graphs and figures.

•

Experiments will usually be marked during the week after they are completed.

•

Disagreements on marks: If you disagree with the marking of your laboratory you should first discuss this with your Demonstrator and Laboratory Supervisor. If an agreement cannot be reached then the matter should be brought to the attention of the Laboratory Coordinator. Any other issues should be discussed with the course coordinator

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WORKBOOK ASSESSMENT CRITERIA The Laboratory Workbook will be marked by the Laboratory Demonstrator. Your workbook will be annotated and the mistakes corrected. The final mark out of 20 for each experiment will be determined according to the guidelines below. Mark 20 19 18 17 16 15 14 13 12 11 5.5

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Table 4. New measurements and calculations for steel cylinders ID h±∆h (mm) D±∆D (mm)

ID

∆h/h

ID

V (mm3)

∆D/D

∆m/m

∆V (mm3)

m±∆m (g)

∆V/V

ρ (g/mm3)

∆ρ/ρ

3 ∆ρ (g/mm )

10. Enter your values for the mass and volume (obtained using the micrometer and/or Vernier calipers) to the table on the whiteboard in the laboratory. 11. Convert your answers to g/cm3. Do they seem like realistic values for a material density?

12. Examine your results for the density. What can you say about the density of the two objects that you have? Are they the same?

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13. Use your values and at least 10 values from the other students to generate a graph of mass against volume. Ensure your graph includes all appropriate labels. Choose the values for your axes carefully so that your data fills the plot (it is not necessary to include the origin). See Appendix 3 for guidelines on graphing. In this experiment the uncertainties will probably be too small to be included as “error bars” on the graph.

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14. If two experimental variables (say x and y) have a linear relationship (such that y=bx) then a straight line is produced when y is plotted against x. The constant b is found by fitting a line of best fit through the data points and then calculating the gradient (slope). How can your graph be used to determine density?

15. Use your graph to determine the density of the stainless steel cylinders examined in this experiment. Add to and annotate your graph as required and include any additional working below.

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VI. FINAL REPORT Your final report must include all the components and information as described in the Report Assessment Criteria and Appendix 5. In addition you should ensure your discussion section addresses the following issues. − Compare the results obtained using the ruler to those you obtained with the micrometer and/or Vernier calipers. What can you say about the two approaches to measurement? − In this experiment only the resolution uncertainty was considered. What other possible sources of experimental uncertainty are there? − Why was it important to measure the experimental uncertainty in this experiment?

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LABORATORY REPORT Why are Experimental Uncertainties Important?

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LABORATORY 2 HOW OLD IS THE UNIVERSE? Workbook Mark:

/20

Report Mark:

/20

Feedback from Demonstrator

Specific Safety Precautions Below is a list of hazards and controls specific to this experiment. Please read it carefully before commencing the experiment and refer to it as necessary during the course of the experiment. Further details can be found in the Risk Assessment document for this experiment, which is available in the laboratory.

Hazard

Control

RSI from using computers

Adjust computer work station for comfortable position. Minimise time spent in front of computer. Arrange workstations to keep screen as far away from the user as practicable. Minimise time spent in front of computer. Ensure air conditioning is on when using computer room. Do not use the computer room if more than 12 students are in the room at once. Keep bags under benches. Keep walkways clear. Do not move around the lab unnecessarily during the experiment.

Eye strain from computer screen Lack of fresh air in computer room

Trip hazard from obstructions in walkways

Personal Protective Equipment Enclosed Footwear is required for this experiment. Safety Glasses are not required for this experiment. Laboratory Coats are not required for this experiment

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I. INTRODUCTION One of the interesting characteristics of galaxies observed by astronomers is that all galaxies (except for a few that are nearby) are moving away from our own galaxy, the Milky Way. This was first discovered by Vesto Slipher in the early 1900s as he examined the spectra of spiral galaxies and noted that they had longer wavelengths (redder) compared to stationary objects. Assuming this wavelength shift was due to the Doppler effect, Slipher concluded that the red-shifted galaxies must be moving away from us. In the 1920’s, Edwin Hubble and Milton Humason were able to measure the distances to galaxies. They plotted a graph of galaxy distances as a function of their velocities, similar to Figure 1. This graph shows that the further away a galaxy is, the faster it is moving away from us.

Figure 1. Hubble Diagram of galaxy velocity versus distance Quantitatively, the Hubble law states that the radial velocity, v is related to the Hubble constant, H, and the radial distance, d by: (1)

v=H d

Astrophysicists interpret this as expansion of the universe much the same way that the distances between raisins in a rising loaf of bread increases no matter which raisin you concentrate on. Furthermore, the best description of gravitation – general relativity – predicts that the universe should be expanding. The expansion of the universe is believed to be the result of an initial beginning or creation known as the "Big Bang". In this experiment you will estimate how long ago this occurred. II. OBJECTIVES 1. 2. 3. 4.

Use a telescope simulator to acquire spectra and apparent magnitudes for galaxies. To use apparent and absolute magnitudes to determine galaxy distances. Use the Doppler shift of spectral features to determine galaxy velociti...