Ib Lab - 03 Measurement Instrument Circus (dc)

International Baccalaureate Physics

4/PSOW

Measuring Instrument Circus Aim: You need practice in taking all measurements with a ± error and then performing calculations to arrive at a final answer in the form, for example :

or

Volume = 28.9 cm3 ± 2 cm3 Volume = 28.9 cm3 ± 6.9 %

There are also some useful “tricks” you can learn to improve the accuracy of your experiments. Think about these methods and include them when collecting your data.

IB Criteria Assessed Data Collection Criteria assessed

Aspect 1

2

3

Level awarded

Pl (a) Pl (b) DC DPP CE

Apparatus: Metre rule, vernier, micrometer, marble, bag of rice, digital scales, mechanical balance, short length of copper wire, 20 sheets of paper, stop watch, ping pong ball, measuring cylinder, tea cup. Method: You must use the available instruments to measure the following items: 1. the diameter of the marble. 2. the surface area of the marble. 3. the volume of the marble. 4. the mass of a grain of rice. 5. the diameter of the copper wire. 6. the time for a ping pong ball to fall from a height of 3 metres. 7. the volume of liquid in a tea cup. 8. the area of the rectangle below.

Data Collection: • Put all your results in a table with a ± heading for each column. • Also specify what instrument you used and the methods you employed to improve the accuracy of your results. • Remember that your ± error estimates are not the only sources of error in the experiments. Look for and think about other causes of errors - e.g.: is the wire the same thickness along the whole length?. There are several problems like this in the experiments. If you spot them, your experimental results will be more accurate. • What assumptions did you make in your results? e.g. - are all rice grains the same size?

© 2006 - Mike Dickinson

8266770.doc

International Baccalaureate Physics

4/PSOW

Internal Assessment Marking Form Crit.

Pl(a)

Pl(b)

DC

DPP

CE

Aspects Research Question: Hypothesis: Variables: c. Identifies a focused c. Relates the hypothesis or c. Selects the problem or research prediction directly to the relevant question. research question and independent p. States the problem or explains it, quantitatively and controlled research question, but it where appropriate. variable(s). is unclear or incomplete. p. States the hypothesis or p. Selects some n. Does not state the prediction but does not relevant problem or research explain it. variables. question or repeats the n. Does not state a n. Does not select general aim provided by hypothesis or prediction. any relevant the teacher. variables. Materials / Control of Variables: Collecting Data: Apparatus: c. Describes a method c. Describes a method that c. Selects appropriate that allows for the allows for the collection apparatus or control of the of sufficient relevant materials. variables. data. p. Selects some p. Describes a method p. Describes a method that appropriate that makes some allows for the collection apparatus or attempt to control the of insufficient relevant materials. variables. data. n. Does not select n. Describes a method n. Describes a method that any apparatus or that does not allow for does not allow any materials. the control of the relevant data to be variables. collected. Collecting / Recording Raw Data: Organising / Presenting Raw c. Records appropriate raw data (qualitative Data: and/or quantitative), including units and c. Presents raw data clearly, uncertainties where necessary. allowing for easy p. Records some appropriate raw data. interpretation. n. Does not record any appropriate raw data. p. Presents raw data but does not Aspect 1 includes units, uncertainties, allow for easy interpretation. significant digits n. Does not present raw data or presents it incomprehensibly. Processing Raw Data: Presenting Processed Data: c. Processes the raw c. Presents processed data appropriately, helping data correctly. interpretation and, where relevant, takes into p. Some raw data is account errors and uncertainties. processed correctly. p. Presents processed data appropriately but with some n. No processing of raw errors and/or omissions. data is carried out or n. Presents processed data inappropriately or major errors are made incomprehensibly in processing. Aspect 2 includes uncertainty bars, max / min slopes (HL), axes with labels and units, best fit line drawn Drawing Conclusions: Evaluating procedure(s) Improving the c. Gives a valid and results: investigation: conclusion, based on the c. Evaluates procedure(s) c. Identifies correct interpretation of and results including weaknesses and the results, with an limitations, states realistic explanation and, where weaknesses or errors. suggestions to appropriate, compares p. Evaluates procedure(s) improve the results with literature and results but misses investigation. values. some obvious p. Suggests only p. States a conclusion that limitations or errors. simplistic has some validity. n. The evaluation is improvements. n. Draws a conclusion that superficial or n. Suggests unrealistic misinterprets the results. irrelevant. improvements.

© 2006 - Mike Dickinson

Level ccc 3 ccp 2 ccn 2 cpp 2 ppp 1 cpn 1 cnn 1 ppn 1 pnn 0 nnn 0

Grade

ccc 3 ccp 2 ccn 2 cpp 2 ppp 1 cpn 1 cnn 1 ppn 1 pnn 0 nnn 0

cc 3 cp 2 cn 1 pp 1 pn 0 nn 0

cc 3 cp 2 cn 1 pp 1 pn 0 nn 0

ccc 3 ccp 2 ccn 2 cpp 2 ppp 1 cpn 1 cnn 1 ppn 1 pnn 0 nnn 0

8266770.doc