Using a Graduate Cylinder
Graduate Cylinders are used to measure the volume of liquids (normal measured in mL)
By using Archimedes Principle you can measure the volume of an object by submerging it.
note: 1 mL = 1 cm3
Warning: be careful not to drop objects into the graduated cylinder; tilt the cylinder and carefully slide the object down the cylinder.
Reading a Graduated Cylinder:
Step 1: make sure that the graduated cylinder is level on a flat surface.
Step 2: gently tap the cylinder to eliminate any air bubbles and recollect liquid droplets.
Step 3: read the graduations on the cylinder at eye level.
Step 4: measure to the bottom of the meniscus (the bottom of the liquids curvature).
Directions: measure the volume of the liquids depicted in the graduated cylinders below and record the value in the space provided.
Make sure to include the estimated digit in your measurement.
1.
2.
mL
7.
3.
mL
8.
mL
4.
mL
9.
mL
5.
mL
10.
mL
6.
mL
11.
mL
mL
12.
mL
mL
Using a Triple Beam Balance to Mass
DISTINCTION: Mass is NOT the same thing as WEIGHT…
o Weight = MASS x GRAVITY
ƒ
On earth, gravity is typically 9.8m/s2
The unit of mass should be recorded in grams, SI unit
Triple Beam Balances are precise to the hundredths place.
examples, 120.34 grams, 57.05 grams, 489.40 grams
Reading a 3-Beam Balance:
Step 1: first check to make sure that the balance levels when the tray is empty, adjust the knob located under the pan to the left to
adjust the scale. Turn the knob until it balances on the mark.
Step 2: place the object(s) to be massed onto the scale and adjust the weights on the beam. Start with the heaviest weight, place in
the largest slot that does not tip the scale. Repeat this with the middle weight and then carefully adjust the smallest weight until
balance is achieved. (Use a delicate touch.)
Step 3: read the value by adding up the value of the three beams.
Step 4: slide the weights on the beams to there zero positions and remove the object from the scale.
WARNING – do not leave objects on the scale or move them with out supporting their weight from the bottom of the scale.
Read the following scales indicting the value that they show.
1. What does the balance above read? _____ g
0 100 200 300 400 500
0 10 20 30 40 50 60 70 80 90 100
0 1 2 3 4 5 6 7 8 9 10
2. What does the balance above read? _____ g
0 100 200 300 400 500
0 10 20 30 40 50 60 70 80 90 100
0 1 2 3 4 5 6 7 8 9 10
3. What does the balance above read? _____ g
0 100 200 300 400 500
0 10 20 30 40 50 60 70 80 90 100
0 1 2 3 4 5 6 7 8 9 10
4. What does the balance above read? _____ g
0 100 200 300 400 500
0 10 20 30 40 50 60 70 80 90 100
0 1 2 3 4 5 6 7 8 9 10
5. What does the balance above read? _____ g
0 100 200 300 400 500
0 10 20 30 40 50 60 70 80 90 100
0 1 2 3 4 5 6 7 8 9 10
Graphing
Draw an axis that you will plot the points on.
Label the axis with a name and unit.
Ex. Volume (cm3)
Scale each axis.
To scale and axis take the largest number to be plotted on the axis and divide it by the number of
squares on the axis, then round up to a nice number.
ex.
Y-Axis (% Error) _
X-Axis (Diameter)
• largest value is 4.9%
• each x-square should be 10 drops
• divide by 10, you get .49%
• round up to 0.5%
• each y-square should be 0.5%
Ex. Sample Graph
Line of Best Fit
A line of best fit is constructed to determine the relationship (equation) between data that appears to be linear.
General Rules:
1. Judge whether the data appears to be in a straight line (linear).
2. Draw a line through the region of your points so:
a. The # of points above and below the line is equal (or near equal).
b. The overall distance of points above the line is equal to the total distance of the points below the
line.
c. The distance that any one point is away from the line is minimized (some points can be eliminated
with proper justification, not just it’s not on the line).
3. The line you draw is not anchored to any data points or the origin.
4. Calculate the slope from two “Good Points”
a. A point where the line of best fit cross the intersection of two grid lines.
b. You may not use data points.
5. Calculate the [slope] using rise/run.
6. Calculate the [intercept] by plugging a “good point” into the slope intercept equation.
[dependent variable] = [slope] [independent variable] + [intercept]
y
=
m
x
+
b
Problem #1, Determining the Volumetric Rate of Rain Fall Jason wants to determine the amount of rain fall that is delivered during a rain storm. Jason waits for an approaching storm and then records the volume of water collected in a graduated cylinder every five minutes during the storm. Jason collected the following data: Time Elapsed (min)) Rain Collected (mL) 5 10 15 20 25 30 35 40 45 1.1 3.7 5.8 8.3 12.5 18.0 21.7 24.4 26.2 1.
2.
3.
4.
5.
Graph the data Jason collected on a sheet of graph paper. Clearly label the axis and title the graph. Is the storm a steady rain or does it surge? Support your answer. Why should we not use a line of best fit? Support your answer. Draw line segments connecting the data points. Calculate the slope of each line segment and record it in a table. Time 0‐5 5‐10 10‐15 15‐20 20‐25 25‐30 30‐35 35‐40 40‐45 (min) Slope 6.
7.
What should the unit of the slope be? The slope represents the average volume of rain during the 5 minute period. When was it raining the heaviest? Support your answer based on the calculated slopes in problem 5. Describe the progress of the storm over the 45 minute period. 8.
Problem #2, It’s Spinning Rick watches a weather vane spinning in the wind. During the period that he makes his observations the wind’s strength seems constant and steady. Rick records the following data: Elapsed Time (sec) 60 120 180 240 300 Total # of Spins 37 72 110 145 181 1.
2.
3.
4.
5.
6.
7.
8.
Graph the data Rick collected on a sheet of graph paper. Clearly label the axis and title the graph. Is the wind steady? Support your answer based on the data. Why is a “line of best is fit” a good option for this data? Support your answer. Draw the “line of best fit”. Calculated the equation of the line and write it along the line. What are the units of the slope? What does the slope mean? Interpolate how much time is required for 50 spins using your equation from question #4. What is different about the event that allows line of best fit for problem #2, but not problem #1?