Chapter 3: Measurements and calculations
length: what is its base unit and symbol?
meter; m
Directly proportional
two quantities that have a constant ratio. Like the cost for potatoes is proportional to weight
what does the prefix centi mean?
10^-2 .01 symbol is c 1 cm = i hundredth of a meter
what does the prefix milli mean?
10^-3 .001 symbol is m 1 mm - i thousandth of a meter
what does the prefix nano mean?
10^-9 0.000000001 symbol is n 1 nm = 1 billionth of a meter
What does the prefix kilo mean?
10^3 1000 symbol is k 1 km = 1 thousand meters
convert 1 foot (ft) to inches (in.)
12 in.
convert 1 pound (lb) to ounces (oz)
16 oz
convert 1 inch (in.) to centimeters (cm)
2.54 cm
convert 1 yard (yd) to feet (ft)
3 ft
convert 1 gallon (gal) to liters (L)
3.78541178 L
convert 1 quart (gt) to fl oz
32 oz
convert 1 gallon (gal) to quarts (qt)
4 qt
convert 1 pound (lb) to grams (g)
453.59237 g
convert 1 mile (mi) to feet (ft)
5280 ft
How do you change from Celsius to Fahrenheit?
Celsius = (Fahrenheit - 32)/1.8
What does not count in determining sig figs in calculations?
Exact Numbers
How do you change from Fahrenheit to Celsius?
Fahrenheit = (Celsius times 1.8) +32
What should a conversion factor do?
Put desired units in correct location and cancel unwanted units
What does SI units stand for?
System International of units
How does significant figures work with multiplication/division?
You use the least number of SIGNIFICANT FIGURES
How does significant figures work with addition/subtraction?
You use the least number of decimal PLACES
Weight
a measure of the force of gravitational attraction
Scientific notation
a method of writing numbers in the form: bcd times 10^6
What are units made up of?
a prefix and a base unit
Mass
a property reflecting the quantity of matter in a sample
How do you change from Celsius to kelvin?
add 273 degrees to Celsius to get kelvin
Equivalency
an expression stating that two quantities with different units represent the same property
What does ambiguous mean?
any zero to the right of a non-zero number with no decimal
mass: what is its base unit and symbol?
gram; g
Base Units
identify quantity measured
volume: what is its base unit and symbol?
liter; L
Density
mass per volume of a substance
what is the equation for density?
mass/volume
Prefixes
scale base units up or down (for larger or smaller measurements)
time: what is its base unit and symbol?
second; s
How do you change form kelvin to Celsius?
subtract 273 degrees from kelvin to get to Celsius