Transcript Goal 1 Notes

Goal 1 Notes
Physical Science
By
Nancy Booth
Physical Science
I. Applied Science vs. Pure Science
II. Technology
III. What is Physical Science?
IV. Problems vs. exercises
A. Problem solving
1.
2.
3.
Known
Unknown
No set way to find answer
B. Critical Thinking
C. Scientific Method
1. Observation
2. Purpose: Question
3. Hypothesis: Proposed answer
4. Experiment
5. Data
6. Data analysis
7.Conclusion
V. Hypothesis vs. theory vs. law
VI. The Experiment
A. Control
B. Constant
C. Independent variable - manipulated variable
D. Dependent variable - responding variable
VII. SI - International System of
Units
A. Base unit for some measurements
1.Distance - meter
2.Mass - kilogram
3.Time - second
4. Temperature - Kelvin scale


Absolute zero - lowest temperature
Kelvin temperature = Celsius temperature + 273
B. Based on 10’s
C. Derived units - combine base units
D. Standards
VIII. Metric Conversions
A. Set-up ratios and cross multiple. Then solve.
Ex.: 20 liters = _____ milliliters
1 liter = 1000 milliliters
20 L
1L
=
X ml
1000 ml
(20 L)(1000 ml) = (1 L)(X ml)
(20 L)(1000 ml)
(1 L)(X ml)
=
1L
1L
B. Factor-Label Method
Ex.: 20 liters = _____ milliliters
1000 milliliters
20 L
1 liter =
1000 ml
=
1L
ml
C. Small Unit
Large Unit
Large Unit
Small Unit
20 L = _______ ml
(divide) ÷
(multiply) ×
300 mg = _______ g
D. Use a number line
King Henry Died Monday Drinking Chocolate Milk
kilo
deca
deci
milli
unit
hecto
centi
micro
E. Use stair steps as a guide
k
h
da
(unit)
d
c
m

IX. Graphs
A. Line graphs - trend or pattern over time
1. y-axis - dependent variable
2. x-axis - independent variable
B. Bar graph - Comparison of numbers
1. Bars don’t touch
2. Numbers must be on one axis
C. Circle graph or Pie graph - Parts of a
whole
1. Parts must add to 100%
2. Numbers for parts do not have to equal 100,
but when converted to a % the total of all
parts equals 100%
Bar Graph



1st Period: 10 – 9th; 2 – 10th; 3 – 11th;
and 4 – 12th.
2nd Period: 8 – 9th; 6 – 10th; 10 – 11th;
and 2 – 12th.
4th Period: 0 – 9th; 12 – 10th; 9 – 11th;
and 8 – 12th.
Pie Graph

Use the data from the bar graph to create
a pie graph with slices for 9th, 10th, 11th,
and 12th.
Line Graph
Time
0 sec
10 sec
30 sec
60 sec
70 sec
80 sec
100 sec
Distance
0m
20 m
50 m
90 m
100 m
120 m
150 m
X. Density
Density refers to how compacted a material is.
mass
density = volume
D = density
m = mass
V = volume
D =
m
V
Units
mg/ml, g/cm3, kg/l
kg, g, mg
ml, l, cm3, dm3
Example 1:
What is the density of a 20 g object
that has a volume of 5 cm3?
D=?
m = 20 g
D = 20 g / 5 cm3 = 4 g/cm3
V = 5 cm3
Example 2:
What is the volume of 20 g of gold?
(Density of gold is 19.3 g/cm3)
D = 19.3 g/cm3
m = 20 g
V=?
V = 20 g / (19.3 g/cm3) = 1.04 cm3
Example 3:
What is the mass of 30 cm3 of
quartz? (Density of quartz is 2.6
g/cm3)
D = 2.6 g/cm3
m=?
V = 30 cm3
m=VD
m = (30 cm3)(2.6 g/cm3) = 78 g
Flash Card - Density
m
D=
V
m
D
V
Density
Units
D - density
mg/ml, g/cm
m - mass
kg, g, mg
V - volume
L, ml, cm
3
3
Density Practice Problems
1. What is the density of an object
that is 30 cm3 and has a mass of 99
g?
2. What is the volume of 69 g of a
liquid that has a density of 1.3
g/cm3?
3. What is the mass of 650 cm3 of
gold? (Gold has a density of 19.3
g/cm3)
4.Determine the density of 45 g of a
solid that is 5 cm by 4 cm by 6 cm?
(NOTE: Volume of a rectangular solid
is V = w h l)
5. Determine the volume of 65 g of
mercury. The density of mercury is
13.6 g/cm3.
6. If you have 33 ml of glue, how
many grams do you have? (Glue has
a density of 1.27 g/cm3)
XI. Scientific Notation
Shorthand method for writing very large
and very small numbers by using powers
of 10.
XII. Rules for Scientific Notation
A. Writing Numbers With Scientific Notation:
1. Move the decimal point so that only one
number remains to the left of the decimal
point.
Ex.: In 36000 the decimal point will move to after
the 3, giving 3.6
2. Count the number of places you moved the
decimal point and use it as the exponent.
Ex.: In 36000 the decimal point was moved 4
places to the left to give 3.6.
 The exponent is negative if the decimal point is
moved to the right.
 The exponent is positive if the decimal point is
moved to the left.
3. Write the number times 10 with the
exponent of the number of places the decimal
was moved.
Ex.: 36000 is therefore 3.6 X 104
B. Writing Numbers from
Scientific Notation:
1. Write the number dropping the X 10.
2. Move the decimal point the number of
places equal to the exponent that was on
the X 10.
Ÿ The decimal point is moved to the right if the
exponent was positive.
Ÿ The decimal point is moved to the left if the
exponent was negative.
Ex.: 7.9 X 106 becomes 7900000. 8.6 X 10-4
becomes .00086.
C. Mathematical Operations using Scientific
Notation:
1.Addition and Subtraction

Before numbers can be added or subtracted that are in
scientific notation the must have the same exponent.
2.Multiplication


Multiply the first numbers and add the exponents.
Check the decimal in the new first number. Relocate the
decimal as necessary and change the exponent as needed.
3.Division


Divide the first numbers and subtract the exponents.
Check the decimal in the new first number. Relocate the
decimal as necessary and change the exponent as needed.
XIII. Significant Figures
Show the precision of an measurement.
The more significant figures the more
precise the measurement. The
measurement show all the digits that are
known plus a last one that is estimated.
XIV. Rules for determining significant figures
1. All non-zero digits are significant.
Ex.: 549 has 3 significant figures.
2. All zeroes between non-zero digits are significant.
Ex.: 3005008 has 7 significant figures.
3. All zeroes to the right of a non-zero digit and to the left
of an expressed decimal point are significant.
Ex.: 5600. has 4 significant figures.
4. All zeroes after a non-zero digit and to the right of an
expressed decimal point are significant.
Ex.: 560.00 has 5 significant figures.
5. All zeroes after a non-zero digit and to
the left of an unexpressed (assumed)
decimal point are not significant.
Ex.:
7600 has 2 significant figures.
6. All zeroes to the left of a non-zero digit
and to the right of an expressed decimal
point are not significant.
Ex.:
.00067 has 2 significant figures.
7. When multiplying and dividing number, count
the number of significant figures in each
number and round the final answer so that it
has the same number of digit as the least
significant number.
Ex.: 54 X 768 = 42444 will be rounded to
2 significant figures or 42000
8. When adding and subtracting number, do the
operation and round the answer to the same
digit as the least significant number.
Ex.: 56 + 34.980 - 6.7 = 84.28 will be
rounded to the ones place or 84
Practice Significant Figures and
Scientific Notation Problems
I. Convert the following numbers to
scientific notation.
1. 76000
2. 876000000
3. .000823
4. .00732
5. .000000881
6. 7610320
II. Change the following numbers to
regular notation from scientific
notation.
7. 6.7 x 107 8. 7.2 x 10-2
9. 8.6 x 104
10. 3.2 x 10-6
11. 8.1 x 10-5 12. 4.03 x 103
III. How many significant figures do each of
the following numbers have?
13. 7620
14. 326.6
15. 1.370
16. .0032
17. .0000302
18. 1.02030
19. .00012
20. 12000
21. 132000.0
IV. Complete the following operations
and record the answers with the
correct number of significant figures.
22. 7.6 x 104 + 3.2 x 103
23. 9.3 x
10-2 x 8.2 x 10-5
24. 8.2 x 10-2
¸ 2.5 x 10-6
25. 5.4 x 10-3 - 6.3 x 10-4
26. 326
x 67.30
27. 99.33 + 162
28. 600 + 170
376.4 ¸ 2.2
29.
30. 9443.56 - 6000
You need to know the following pieces of lab
equipment. Make a study guide by drawing the
following pieces found on page xxii in your lab manual:
1. Test tube
2. Scoop
3. Forceps
4. Triple-beam balance
5. Funnel
6. Watch glass
7. Beaker
8. Dropper pipet
9. Utility clamp
10. Test tube rack
11. Tongs
12. Stopper
13. Ring stand
14. Graduated cylinder
15. Flask
16. Thermometer
17. Iron ring