basic units lengthmeters masskilograms timeseconds
TRANSCRIPT
Basic Units
•Length meters•Mass kilograms•Time seconds
•Temperature Kelvin
•Amount Chm Mole
•Current Ampere
•Luminous In Candela
Metric Prefixes•Mega(M) Nano(n)
•Kilo(k)
•Milli(m) Centi(c)
•Micro()
Metric Prefixes•(M) = 106 (n) = 10-9
•(k) = 103
•(m) = 10-3 (c) = 10-2
•() = 10-6
Accuracy
•How close you are to the real answer
Precision•How well one can repeat his or her work
•Repeatability
Uncertainty•All measurements have a degree of unreliability
•Usually in the last digit of a measurement
Significant Digits•Meaningful digits in a number
Multiplication Uncertainty
• The answer should have the same number of significant digits as the multiplier with the least number of SD
• Same for division
Addition Uncertainty• When adding, line up decimal
place & add
• The decimal places in the answer should = the least
• Same for subtraction
Determining Significance
• All non-zero digits
• All zeros between non-zero numbers
• All trailing zeros if there is a decimal place
Scientific Notation•M x 10n
•M = 1.00 M < 10.00
•n = an integer
Conversion Factor• Ratio equal to one
• 12 inches/1 foot
• Multiply one unit by a conversion to obtain another unit w/o affecting magnitude
Convert:•2.50 cm to Mm
•4.2 ns to ms
•3.15 kg to g
Determine the length in miles of a light year
• Light year = distance light travels in one year
• c = 3.0 x 108 m/s
• 1 mile = 5280 ft
• 1 inch = 2.54 cm
Convert:
4.35 kg/L to mg/L
2.31 mm/ns to cm/Ms
Calculate the volume in m3 occupied by 750 kg of gas with
1.50 g/L1 cm3 = 1 mL
Calculate the mass in kg of a board that has
dimensions of 250 mm x 4.0 x 104 m x 2.5 m and
had a density of 0.80 g/mL1 ml = 1 cm3
Calculate the density of a 3.14 x 103 kg cylinder that 5.0 m
long & has a diameter of 2.0 m.
How many nm willan object travel in
1/132 ks at720 miles per hour
1 inch = 2.54 cm1 mile = 5280 ft
Measurements•Work problems
5 - 12 on page 25
Sig. Figs.•Work problems 17 - 24 on page
25
Conv. Factors•Work problems
28 & 36 on page 24
Measurements•Work problems
5 - 12 on page 25
Define all the key terms on page 24
Work problems13 - 16 onpage 25
Conversion Factors
•Work problems 37 - 46 on page
25