Mass vs. Volume (Density Lab)
Rubric #2 is not found in any particular place in the lab. The following are the requirements for #2: -Lab must be in the corre
ct order. Follow this form as a guide for the order. -The lab must be neat, legible, and representative of an AP student.
Technically, DV comes first. But either order is accepted for credit. Give the lab either an IV/DV title or a common title.
Purpose: To determine the mathematical and graphical relationship between mass and volume.
IV: Volume (cm3)
Units on IV and DV needed for full credit.
The purpose is always the same. Just make sure to use the correct variables at the end. Switching the order of “mathematical” and “graphical” is OK. Also switching the order of the variables is OK.
DV: Mass (g)
Ruler 6 Blocks Triple beam balance
All equipment needed must be listed. Simple materials such as lab book, calculator, and pencil are not needed unless they played a special part in the lab. The equipment list and diagram can not be used for the same credit.
The diagram must be labeled with the appropriate range. For example; in this lab, the block volumes range from 64 cm3 to 1728 cm3.
The diagram must be at least 1/3 of a page in size, give the gist of the lab procedure, include labels, and must show effort. Attempt to not just draw a materials list. Rather, show the materials in action.
Volume: 64 cm3 – 1728 cm3 Mass: 3 g – 500 g
Both of the two measured variables must be integrated into the diagram.
? ? ? ? ? ?
Measure length, width, and height of the iron block in centimeters with the ruler. Calculate the volume of the block in cm3. Tare triple beam balance to zero. The general rule for a procedure Place block on the triple beam balance and measure the mass in grams. is that it could be passed to an Repeat steps 1-4 for three trials. educated stranger with no experience in the class and they Repeat steps 1-5 with the remaining five blocks.
could reproduce the entire lab from the procedures and diagram alone.
DO NOT include these in the procedures: -Get materials -Record data -Do lab -Make data table -Do calculations -Make graph -Analyze data -Clean up -Any reference to the instructor A minimum of 3 trials is required for all DV data.
The data must be fully boxed in and a straight-edge must be used to make straight lines. T-charts are partial credit. Taped data table printouts are not recommended.
Each title box needs a variable and a unit. Averages need a place on the table as well because they will be graphed later.
9 8 10 11
Length(cm) 1.11 2.05 2.90 3.35 3.90 3.99 5.16 6.02 Mass (g) Trial 1 3.24 17.76 60.52 113.0 110.3 154.42 295.01 499.02 Mass (g) Trial 2 3.20 17.77 60.54 114.0 110.9 154.41 294.94 497.86
Volume(cm3) 1.41 8.00 27.51 37.70 59.20 67.73 127.71 214.17
Height(cm) 1.20 1.98 3.06 3.31 3.92 4.12 5.00 5.90
Width(cm) 1.06 1.97 3.10 3.39 3.87 4.12 4.95 6.03
Mass (g) Trial 3 3.21 17.77 60.49 114.6 111.3 154.48 296.00 500.02
Average mass (g) 3.22 17.77 60.52 113.8 110.8 154.44 295.32 498.97
Instead of just “average”, you must write “average mass”.
Each lab requires changing the IV a minimum of 8 times. The minimum is lowered if the student is not provided enough materials to change the IV 8 times.
To obtain the best graph possible, make sure the largest value is at least 10-times greater than the smallest value. Otherwise, it can be difficult to determine if the line is curved or linear.
This is copied from the square piece of paper with the written relationships. Fill in X and Y with your variables and units.
As volume increases, mass increases proportionally. Mass is directly proportional to time.
250 As mass (g) increases by 2.316 (g), volume (cm)3 increases by 1 (cm)3.
100 Volume (cm)3
This number will always be “1” because the slope is always a value over 1.
Both axes must have correct labels, units, and incrementing.
The written relationship and the physical meaning of the slope must either be written on the graph sketch itself or on the page housing the graph sketch.
Additional graphs may be required under the following circumstances: ? ? ? Lab Extensions Multi-part Labs Linearized Graphs
Suggestions for lab notes is found in the lab notes examples guide
These units are always the y-axis units over the x-axis units.
New Terms Mass – The amount of particles in something.
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The general equation is the process of converting the math model into the general equation that can be found in any textbook.
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Volume – How big something is.
The new terms are given to you by the instructor. You must define them in simple terms. Do not use a dictionary.
The problem example should be like that found in a textbook.
Y-Intercept Explanation The y-intercept should be zero because as the volume becomes infinitely small, there are fewer and fewer particles of matter. The theoretical y-intercept is an open circle because once the volume equals zero the system ceases to exist.
Problem Example What is the mass of air in a living room with dimensions 4.0 m x 6.0 m x 2.5 m? ( ( ) ( ? ) ( ) ( ) )
The y-intercept explanation comes in 2 parts:
Error Analysis One error could be assuming the masses were perfect cubes when in fact they had rounded edges. This error would cause the measured volumes to be larger than in actuality. This would shift every point on the graph, giving a yintercept under the actual value.
1) 2) 3)
What should it be theoretically or what it represents. Is it an open or closed circle
The error analysis comes in 3 parts: Identify the error Determine what will be effected Explain how this will change the numeric result (slope or y-int.)
Logger pro will produce a print-out of the data table. There must be labels and units in the headings. Units are not necessary for each value because if you attempt to do so, it will create an error in logger pro.
Once you plot the points you must do a linear or a curve fit for the line.
The graph must be auto-scaled from zero. This prevents nonlinear lines from appearing linear.
The graph may be done by hand or with another program if the student wishes. It must adhere to the same standards as the graph provided by logger pro.
The y-axis increments do not have to be the same as the x-axis.