 # Nature of Science - Notes I

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Nature of Science - Notes I
Objective: Use triple beam balance, meter stick, and graduated cylinder Point out that objectives are what they are responsible for KNOWING in this class. All notes, activities, and tests will be based on the OBJECTIVES for the course

an instrument used to measure mass
Triple Beam Balance Why is it called a triple beam balance Discuss difference between QUANTITIES and UNITS Example: Time - min, hr, sec,years, etc Length – feet, meters, miles, etc an instrument used to measure mass

units - kilograms or grams
mass - Amount of matter in an object units - kilograms or grams weight Measure of the pull of gravity on an object Would MASS change if you go to the moon? Would WEIGHT change if you go to the moon? Pass around 1 kilogram 1 gram is the mass of a paperclip 1 Newton weighs about a ¼ pound ---- a stick of butter units - Newtons

Using a Triple Beam Balance
1. Transporting and storing the balance Always use 2 hands ; do not allow pan to move Store with all mass all the way to the left Demonstrate carrying balance; emphasize expense -- \$100 each and consequence for horseplay in lab Identify location of balances in classroom and teacher policies on handling equipment..

Using a Triple Beam Balance
2. Zero the balance Slide all masses to left Adjust thumbscrew until arrow stays on zero line Demonstrate placing object on balance

Using a Triple Beam Balance
3. Placing object on pan GENTLY!! There should be no sound. Never press on the pan with your hand. Demonstrate placing object on balance

Using a Triple Beam Balance
4. Determine measurement Slide large mass one at a time until it “bottoms over”, then move it BACK one Slide medium mass one at a time until it“bottoms over”, then move it BACK one Read a step then demonstrate it Slide small mass at little at a time until it balances Add all 3 measurements for mass in grams

Example 1 g g g Students should draw the arrows on their notes paper ANSWER: = grams

Example 2 g g g ANSWER: = grams

Example 3 g g g ANSWER: = grams Point out that you DO need the .0 !! This instrument measures to the nearest 1/10 of a gram.

Example 4 g g g ANSWER: = grams Some students will want to call this 77 grams …… show where smallest mass would have to be for 77 g

2. Get triple beam balance and objects A, B, & C
Mass Practice 1. Form groups of 3 2. Get triple beam balance and objects A, B, & C 3. Each person mass one object, others verify 4. Record masses of objects A, B, & C on your paper 5. Return balance and objects Establish acceptable noise level and pace right now!! Make known procedure for getting teacher assistance ie SILENT hand in air Give time limit ( 5 min?) for all equipment to be returned and students in seat!

an instrument used to measure length
Meter Stick Review difference between QUANTITIES and UNITS Example: Time - min, hr, sec,years, etc Length – feet, meters, miles, etc Ask students how big a meter is How big a centimeter is How many cm are in a meter? Show where meter sticks are kept in your room an instrument used to measure length

Which side?! Point out that some meter sticks have ENGLISH units on one side. They need to know which side to use!! Show how inches are usually expressed as FRACTIONS, and meters are DECIMALS

To change centimeters to meters: _____________by _________
100 1 meter = _____ centimeters 1/2 meter = _____ m = _____ cm .5 50 To change centimeters to meters: _____________by _________ divide 100

34.2 cm = ______ m 158 cm = ______ m 3.7 cm = ______ m ______cm = 2 m
Try these: 34.2 cm = ______ m 158 cm = ______ m 3.7 cm = ______ m ______cm = m ______cm = m .342 1.58 .037 Give students time to copy the GIVEN measurement, and then figure out the missing measurement Stress LEARNING……don’t just wait for answers to come up…..don’t look at neighbor 200 11.1

Are the numbers METERS?? Or CENTIMETERS?? 34.4 cm m

40.1 cm or .401 m

2. Get meter stick and objects A, B, & C
Length Practice 1. Form groups of 3 2. Get meter stick and objects A, B, & C 3. Each person measure one object, others verify 4. Record lengths of objects A, B, & C on your paper 5. Return meter stick and objects Remind about acceptable noise level and pace. Make known procedure for getting teacher assistance ie SILENT hand in air Give time limit ( 5 min?) for all equipment to be returned and students in seat!

an instrument used to measure volume
Graduated Cylinder AGAIN Review difference between QUANTITIES and UNITS Example: Time - min, hr, sec,years, etc Length – feet, meters, miles, etc Talk about size of a liter and a ml Point out a ml is a cm cubed an instrument used to measure volume

unit - liter or milliliter
volume amount of space an object occupies unit - liter or milliliter

Each line is worth? 10 ml How much water? 230 ml 300 200 100
There is NOT a place to put these answers on notes papers Point out that different size graduated cylinders have different scales. First determine what each little line is worth on each Measure to lowest part of miniscus 230 ml 100

Each line is worth? .1 ml How much water? 6.8 ml 7 6 5
Note that this much be a much skinnier graduated cylinder 6.8 ml 5

70 Each line is worth? 60 2 ml 50 How much water? 40 56 ml 30 20

TRY THESE 1 mL 10 mL 37 mL 240 mL .1 mL 5 mL 6.6 mL 95 mL 40 30
Each mark: Amount of H2O: 300 200 Each mark: Amount of H2O: 1 mL 10 mL 37 mL 240 mL Students should write markings and draw water levels on notes sheets and answer questions. Again ---- stress engaging and learning! 7 6 Each mark: Amount of H2O: 100 50 Each mark: Amount of H2O: .1 mL 5 mL 6.6 mL 95 mL

in a graduated cylinder 3. Others verify
Volume Practice 1. Form groups of 3 2. Each person determine the amount of water in a graduated cylinder 3. Others verify 4. Record values on notes page & groupsheet Insist that students FOLLOW DIRECTIONS. Give non verbal cue for rotating to stations. (flash lights, blow whistl, etc)

REVIEW

REVIEW What is the unit to measure MASS? What quantity does a graduated cylinder measure? What device is used to measure MASS?

4. What is the LENGTH of the line? (include the UNIT)
REVIEW 4. What is the LENGTH of the line? (include the UNIT)

5. What is the MASS ?(include the UNIT)
REVIEW 5. What is the MASS ?(include the UNIT) g g g

6. What is the VOLUME of water? (include the UNIT)
REVIEW 6. What is the VOLUME of water? (include the UNIT) 9 8 7

What is the unit to measure MASS?
REVIEW What is the unit to measure MASS? What quantity does a graduated cylinder measure? What device is used to measure MASS? gram or kilogram volume Click to show answers triple beam balance

4. What is the LENGTH of the line? (include the UNIT)
REVIEW 4. What is the LENGTH of the line? (include the UNIT) Click to show answers 26.1 cm

5. What is the MASS ?(include the UNIT)
REVIEW 5. What is the MASS ?(include the UNIT) g g g Click to show answer 415.5 g

6. What is the VOLUME of water? (include the UNIT)
REVIEW 6. What is the VOLUME of water? (include the UNIT) 9 8 7 8.8 mL Click to show answer