Robinson- Measurement

Question Answer
standard of measurement an exact quantity that people agree to use for comparison
examples of standard measurement hands, an arm's length, feet
two basic systems of measurement English and metric system
Why is metric system used in science? all SI standards are universally accepted and understood by scientists
System most commonly used in United States English system
SI is the standard system used worldwide Metric system
two sources of error when making measurements equipment/ instrument error and human error
basic unit of length in metric system meter (m)
What are more common prefixes for measuring length? centimeter (cm), millimeter (mm), kilometer (km)
What piece of equipment is used to measure length? ruler, meter stick
Two rules for measuring length accurately? use metric side of ruler, begin reading at first mark (not edge of ruler)
Distance around the outside of a figure perimeter
formula for perimeter p= s + s + s + s
label for perimeter cm
area amount of surface space
formula for area A= l x w
label for area cm squared
volume amount of space an object takes up (occupies)
formula for volume V= l x w x h
label for volume cm cubed or cc
mass the amount of matter in an object (molecules)
basic unit of mass in metric system gram (g)
common prefixes used for mass milligram (mg) and kilogram (kg)
Balance piece of equipment used to measure mass
tare weight the weight of paper or container
3 rules for using balance accurately carry using two hands, never place chemicals directly on balance, slide weights to zero before removing object
weight the pull of gravity on the object
metric unit for measuring weight Newtons (N)
spring scale piece of equipment unsed to measure weight
difference between mass and weight weight can vary depending on the pull of gravity
liquid volume amount of space an object takes up
basic unit of liquid volume liter
common prefixes for liquid volume milliliter (ml)
piece of equipment used to measure liquid volume graduated cylinder
Why are beakers and flasks not use- need to determine volume their results are not accurate
meniscus curvature of the liquid due to surface tension and capilllary action
2 rules for measuring volume accurately Place on flat surface and read at eye level; take reading from the bottom of meniscus
water displacement when an object is placed in water, the object's volume is equal to the amount of water displaced
volume of jagged stone Fill graduated cylinder part way. Take reading and record. Add object slowly. Take reading and record. Add object slowly. Subtract first reading from second.
density mass per unit volume of a material (amount of molecules in a given space)
3 pieces of equipment needed to find density balance (mass), ruler, or graduated cylinder (volume)
formula for density D= m/v, M= V x D, V= m/d
label for density g/cm3 or g/cc or g/ml
density for water 1 gm/cc
density of cork 0.3 g/cc
copper 8.9 g/cc
What determines if an object will float or sink? its density compared to that of water (1 g/cm3)
If an object floats its density is less than water
If an object sinks if its density is more than water
Does density change? No, it's a constant
Temperature How hot or cold an object is- relates to the speed of molecules
3 temperature scales degrees F, C, K
Which is the SI unit of temperature? degrees K
Equipment used to measure temperature? thermometer
boiling/condensation point of water 212 F degrees, 100 C degrees, 373 K degrees
freezing/melting point of water 32 F degrees, 0 C degrees, 273 K degrees
absolute zero -459.4 F degrees, -274 C degrees, 0 K degrees
body temp 98.6 F degrees, 37C degrees, 310 K degrees