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GRAPHING AND VARIABLESX axis—holds the independent
(manipulated) variableY axis—holds the dependent
(responding) variable***DRY MIX***
ACTIVATOR:WORD SPLASH--MEASUREMENTList as many terms or phrases
that we’ve discussed in unit 2 that deal with measurement
DATA TABLES AND VARIABLES
X (INDEPENDENT)
Ex: Volume (mL)
Y (DEPENDENT)
Ex: Mass (grams)
2.0 7.9
3.0 16.2
4.0 25.0
5.0 32.3
SLOPEIs determined by the first and
last data pointsLast y – first y = y2 - y1
last x – first x x2 - x1
Ex: 32.3 – 7.9 = 24.4 = 8.15.0 – 2.0 3.0
DIRECT VS. INDIRECT PROPORTIONS
DIRECT INDIRECT (aka INVERSE)
Shows a positive slope
Shows a negative slope
both factors increase or both factors decrease (do the same thing)
Factors do opposite things
Ex: speed = distance/time density = mass/ volume
Ex: area = length x width
Graph: Graph:
FLIPPED ASSIGNMENT--DENSITY
Visit the following website:http://mswipc.com/problem_sets/density/density_sample_problems.htm
Review all 3 types of density problems posted on this page before class tomorrow.
ACTIVATOR: Explain why these substances are layered?
DENSITY DEMONSTRATIONS: (TEACHERTUBE.COM)
1. The density of liquids2. Underwater volcano3. The density of water is 14. Dr. Reich’s density labhttp://www.teachertube.com/viewVideo.php?video_id=7593
FOR DENSITY LAB:--follow your procedure !!!---DO NOT MOVE CHAIRS AROUND---MUST KEEP GOGGLES ON AT ALL TIMES at
station 2!!!---PART OF YOUR GRADE IS BASED ON
CLEAN UP---WHEN USING SOAP TO WASH CYLINDER,
ONLY USE 1 DROP!---stay with your group and stay quiet!!--- calculate all densities after coming to sit
down
On your data table, add:PART C:Mass of red block=Length =Width=Height=Volume =Density =
DENSITY LAB CONCLUSIONSANSWER 1—5
For #2 you will need these accepted values.
% error = measured – accepted x 100accepted
Water = 1.00 g/mLLiquid A (isopropanol)= 0.786 g/mLLiquid B (glycerin) = 1.26 g/mLSolid sinker (lead alloy) = 11.40 g/ccRed wood (alder) block = 0.4 g/cc
DENSITYDENSITY = MASS
VOLUME**this is a direct proportion**As mass increases, volume increases (or
as mass decreases, volume decreases)Units that measure density:Solids: g/cm3 liquids: g/mL gases: g/L
**see density chart p. 38
Specific gravityThe density of a substance
compared to water’s density (1.0 g/mL)
Float = density less than waterSink = density greater than
water
p. 40 (SHOW WORK AND INCLUDE CORRECT UNIT)
#1. What is the density of a block of marble occupying 310. Cm3 and a mass of 853 grams?
#2. Diamond has a density of 3.26 g/cm3 and a volume of 0.351 cm3. Find the mass.
#3. What is the volume of a sample of mercury having a mass of 76.2 grams and a density of 13.6 g/mL?
ANSWERS1. 2.75 g/cm3
2. 1.14 grams
3. 5.60 mL
4) If a sample of lead is cut inhalf, will its density change?
Explain why or why not.
No b/c mass AND volume both change
by the same factor
5) Find the density in grams/mL of aliquid having a mass of 2 kg and a
volume of 2900 mL.
What might this liquid be?(see p. 38) Would it sink or float in water?
2000 grams / 2900 mL = 0.7 g/mL
It would float because it’s density is less than water’s
SUMMARIZER: DENSITY 3-2-1Name 3 measurements the
density formula involves.Give 2 units that measure
density.Give 1 reason an object may float
in water.
ACTIVATOR: (using your calculator)Calculate the density of a gas
with a mass of 253 grams and a volume of 3.5 L.
SHOW YOUR WORK
ACTIVATOR:Using the Density chart below, name
2 substances that will float in water AND 2 substances that will sink in water.
Brass 8.55Gold 19.3Iron 7.8Uranium 18.7Ice at 0 C 0.92Wood 0.67
Homework
Density handout front 1—13 back ODD****also read LAB carefullyFinish IPAD activity
DENSITY HANDOUT ANSWERS-FRONT SIDE 1. 1.20 g/mL 2. 3.3 g/cc (could be Aluminum which has density of
2.7 g/cc) 3. 700 grams 4. 200 mL 5. 0.757 g/cc 6. 73 mL 7. 1.12 g/mL 8. 290 grams 9. 70 cc 10. 1.53 g/mL 11. 1.8 g/cc 12. 600 grams 13. 1.44 g/mL
BACK---ODD 1--201. 0.23 g/cc3. 0.14 g/cc5. 0.21 g/cc7. 0.27 g/cc9. 0.11 g/cc11. 2.0 g13. 2.7 g15. 2.6 g17. 90. cc19. 41 cc
EXTRA PRACTICE --DENSITY1. 302. 2.03. 24. 3.05..
SUMMARIZER—using the density formula
How is density calculated?
How is mass calculated?
How is volume calculated?
ACTIVATORCalculate the volume of a block
of wood having a denisty of 0.78 g/cm3 and a mass of 300 grams.
WARM UP—DENSITY & GRAPHING 1. Calculate the density of a liquid having a mass of 35 grams and a volume
of 111 mL 2. Calculate the mass of a solid having a density of 2.5 g/cc and a volume of
3 cc. 3. Calculate the volume of a block with a mass of 9.0 grams and a density of
45 g/cm3. 4. Find the density in grams/mL of a liquid having a mass of 3.4 kg and a
volume of 1.0 L. 5. If a sample of gold is cut in half, would its density change. EXPLAIN WHY
OR WHY NOT.
ANSWER THE FOLLOWING QUESTIONS USING THE DATA TABLE BELOW: MASS (g) VOLUME (mL) 3.0 15.0 4.0 10.0 5.0 6.0
6. Calculate slope of the graph’s line. 7. Is this a direct or indirect relationship? 8. What is the responding variable? 9. What is the independent variable?
SUMMARIZERDescribe how the density is
measured for an irregular shaped solid VS. a rectangular shaped solid.
p. 42 #5 p. 54 #1, 2p. 57 #7-10p. 59 # 13b,c 14a,b 17-19,
22a,b 32b, 33b
ACTIVATORPut the object’s in the lab in order of
least to greatest density:
Water = 1.00 g/mLLiquid A (isopropanol)= 0.786 g/mLLiquid B (glycerin) = 1.26 g/mLSolid sinker (lead alloy) = 11.40 g/ccRed wood (alder) block = 0.4 g/cc
Which ones would sink in water? Which ones would float in water?
QUIZ-- DENSITY= mass/volume
REMEMBER SIG FIGS AND UNITS!!SHOW WORK!!1. Calculate the density of a solid having
a mass of 45 grams, a length of 2 cm, a width of 3 cm, and a height of 1 cm.
2. An object’s density is 3.6 g/cc. It is put into a graduated cylinder initially having 25.0 mL. The water level rises to 25.2 mL. What is the object’s mass?
3. Find the volume of an object with a mass of 25 kg and a density of 5 g/mL.