Measurement

Systems of Measurement English system: what the US typically uses to measure SI system: what the scientific community uses to measure ~ also known as the metric system ~ based upon the number 10

LENGTH use a ruler to measure English system: inches, feet, yard, miles SI system: meter (m), centimeter (cm), millimeter (mm), kilometer (km)

MASS amount of matter in an object use a balance to measure English system: pound, ounce SI system: gram (g), milligram (mg), kilogram (kg)

132.5 g 133.3 g 34.5 g 150.5 g

VOLUME how much space something takes up use a ruler OR graduated cylinder -overflow can to measure English system: quarts, pints, gallons, cubic inches (in3), cubic feet (ft3) SI system: cubic centimeters (cm3), milliliters (mL)

ways to calculate volume regular volume (flat sides): rectangular or cubed object formula: length x width x height ~ doesn’t matter which order ~ answer will be cubed (to the third power) ex: 3 cm x 4 cm x 2 cm = 24 cm3

10.3 cm 13.7 cm 0.9 cm 4.7 cm

use the displacement method irregular volume: object without flat sides use the displacement method ~ find out how much space the object takes up (volume) by “displacing” a certain amount of water done with a graduated cylinder (if small) or overflow can (if large) resulting answer will be in mL *** 1 cm3 = 1 mL ***

Graduated Cylinder method Place enough water in the cylinder so object will be covered completely once placed in the cylinder. Read the volume of water in the cylinder. Place object in the cylinder. Read the new volume of water in the cylinder. Subtract the two volume readings to find your volume of the object.

14 mL 12 mL 16 mL 14 mL

Overflow Can Method Fill water to the very lip of the overflow spout. Place an empty graduated cylinder under the overflow spout. Place the object in the can and catch the water flowing out in the graduated cylinder. Read the amount of water in the graduated cylinder. ~ the amount in the graduated cylinder IS the volume of your object

WEIGHT measures the force of gravity on an object’s mass use a scale to measure will be different at different locations ~ 120 lbs on Earth would be 20 lbs on the Moon ~ in space, there’s no gravity so there’s no weight!

DENSITY amount of matter in a given amount of space ***important identifying characteristic of materials formula: mass / volume

ex: an object has a mass of 5 g and a volume of 10 cm3 D = m / v D = 5 grams / 10 cm3 D = 0.5 g/cm3

ex: an object has a mass of 5 g and a volume of 10 mL D = m / v D = 5 grams / 10 mL D = 0.5 g/mL