Ch 2: Measurement and Problem Solving Flashcards
(30 cards)
What are the SI units for: length mass time temperature amount of substance electric current luminous intensity
Meter (m) Kilogram (kg) Second (s) Kelvin (K) Mole (mol) Ampere (A) candela (cd)
How is the meter defined?
The standard of length:The definition of a meter, established by international agreement in 1983, is the distance that light travels in vacuum in 1/299,792,458 s (The speed of light is 299,792,458 m/s.).
How is the kilogram defined?
The standard of mass: The kilogram is defined as the mass of a block of metal kept at the International Bureau of Weights and Measures at Sèvres, France. A duplicate is kept at the National Institute of Standards and Technology near Washington, D.C.
How is a second defined?
The standard of time:The second is defined, using an atomic clock, as the duration of 9,192,631,770 periods of the radiation emitted from a certain transition in a cesium-133 atom.
What does M mean?
mega-
million
10^6
1,000,000
What does k mean?
kilo-
thousand
10^3
1,000
What does d mean?
deci-
tenth
10^-1
0.1
What does c mean?
centi-
hundredth
10^-2
0.01
What does m mean?
milli-
thousandth
10^-3
0.001
What does μ mean?
micro-
millionth
10^-6
0.000001
A kilogram is equivalent to how many lbs?
1 kg = 2.205 lbs
An inch is equivalent to how many cm?
1 in = 2.54 cm
A mile is equivalent to how many km?
1 mi = 1.609
A liter is equivalent to how many quarts?
1 L = 1.057 qt
What is a derived unit?
A unit formed from other units.
E.g. many units of volume, a measure of space, are derived units (m^3, cm^3, mm^3)
L and mL are NOT derived units
What kind of numbers have an unlimited number of significant figures?
discrete objects, defined quantities, and conversion factors
What numbers are ambiguous?
Trailing zeros at the end of a number, but before an implied decimal point, and should be avoided
What is the rule for rounding?
Use only the last digit being dropped to decide in which direction to round. Ignore all digits to the right of it.
What is the rounding rule for multiplication and division?
Round only at the end. The result of multiplication and division carries the same number of significant figures as the factor with the fewest significant figures.
What is the rounding rule for addition and subtraction?
The result carries the same number of decimal places as the quantity carrying the fewest decimal places.
What is the rule for rounding both multiplication/division and addition/subtraction?
Do the steps in parentheses first, determine the correct number of significant figures in the intermediate answer without rounding, then do the remaining steps.
What is mass?
A measure of the quantity of matter with it.
What is weight?
A measure of the gravitational pull on that matter.
What is volume?
A measure of space.
