Let’s look at the chart again.
Meter, Liter, GramStandard Unit SI
Let’s look at the chart again.
Kilo
EXAMPLE: 1000m = 1 km1000 L = 1 kL1000g = 1kg
Let’s look at the chart again.
Centi
• 100 cm = 1m• 100 cg = 1 g• 100 cL = 1 L
Let’s look at the chart again.
milli
• 1000 mL = 1L• 1000 mg = 1g• 1000 mm = 1m
• EX. How many meter are in 925 km?
925 km ? m=
Do the Math
925 km xkm
m
1
1,000
1 x 1=
925 x 1,000
1=
925,000= 925,000
LecturePLUS Timberlake 11
Solution
Unit plan: days hr min seconds
1.4 day x 24 hr x 60 min x 60 sec 1 day 1 hr 1 min
= 1.2 x 105 sec
Accuracy versus Precision
• Accuracy: how close you are to the actual value
• Precision: the ability to measure with exactness, repeatability.
Accuracy versus Precision
• VALUES IN DATA: • 12.33 cm• 12.21 cm• 12.27 cm• 12.24 cm
• ACTUAL VALUE: 99 cm
The data is precise, but not accurate
Accuracy versus Precision
• VALUES IN DATA:• 95.89 cm• 101.22 cm• 96.80 cm• 99.2 cm
• ACTUAL VALUE: 99 cm
The data is accurate but not precise
Accuracy versus Precision
• VALUES OF DATA:• 14.53 cm• 99.49 cm• 57.90 cm• 32.84 cm
• ACTUAL VALUE: 99 cm
The data neither accurate nor precise
Accuracy versus Precision
• VALUES OF DATA:• 99.87 cm• 99.12 cm• 98.99 cm• 99.53 cm
• ACTUAL VALUE: 99 cm
The data is both accurate and precise.
CALCULATING DEGREE OF ERROR
• Measurement – Actual Value X 100 Actual Value
EX: measurement is 29. Actual Value is 27.5
29 – 27.5 X 100 = 5.45% percentage of error 27.5
OTHER MEASUREMENTS
• VOLUME = L , cm3, cc• MASS= g• LENGTH= m• DENSITY = g/ml, g/cm3
LET’S REVIEW
The safest way to dilute concentrated sulfuric acid is to add:
– A series of small volumes of water to the acid while stirring.
– The acid to water slowly while stirring constantly.– The acid to a small volume of water and then add
more water.– Dilute sulfuric acid to a small volume of the
concentrated acid.
Intensive versus Extensive
• Intensive – Molecule Activity
• Extensive – Amount of matter
• WHAT HAPPENED TO THE DENSITY OF THE SUBSTANCE???
What is the most appropriate unit of measure for reporting the density of a solid?
– g/cm3
– g/cm– g/L2
– g/mm2
Volume is space the matter takes up
cm3 = cc = mL
• These are the measurements of volume.
• The METRIC measurement for VOLUME is mL
• There will be at least three questions when you will need to know this.
Which of the following pieces of equipment would be most appropriate for measuring the volume of a marble?
How many significant figures
• 32.983• 8.000• 4839.4• 0.000000000000023• 23,000.0• 450,057
What do these PREFIXES mean
• Kilo• Centi• Milli
KILO
• Greek for ‘thousand’• Means 1000 times larger
Centi
• Latin for ‘hundred’• Mean 100 times SMALLER
milli
• Latin for ‘thousand’• Means 1000 times smaller
Temperature Conversions
Ko= Co + 273 Co = Ko - 273Fo = 9/5 (Co +32) Co = 5/9 (Fo-32)
WHAT YOU’RE GIVEN ON THE STAAR EXAM AND TAKS
0 Co = 273 Ko
Precision and Accuracy
Team 1- 2.65 cm Team 2 - 2.75 cm Team 3 - 2.80 cmTeam 4 - 2.77 cm ACTUAL MEASUREMENTTeam 5 - 2.77 cm 2.70 cm Team 6 - 2.65 cm
Accurate, precise, both or neither
Percentage of Error
• Measurement – actual value X 100 = %
actual measurement
EXAMPLE: team 1 2.65
2.65 – 2.70 X 100 = 1.85 % 2.70
The quantitative measurement among the following is:
– The girl is taller than the boy.– The girl is tall for her age.– The girl is the tallest in the class.– The girl is 7 feet tall.
