Name______

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Measurement: To find the amount of something as compared to a standard.

Early Measurement: Body parts were the earliest forms of measurement. This was convenient because it was easyto use and the measuring device could not be misplaced. Examples:

  • Uncia: the width of a thumb (about 1 inch)
  • Cubit: the distance from the tip of the middle finger to the end of the elbow.
  • Foot: the length of a person’s foot. (about 12 inches)
  • Span: the distance from the tip of the thumb to the tip of the pinkie on an outstretched hand.
  • Yard: the distance from the tip of the middle finger to the nose.

Standardized Measurement: Measurements with body parts were not accurate because people come in all different sizes. Everyone agrees to use the same unit for measurement in a standardized system. Thus, the foot of the king was taken to be the standard unit of length. Sticks were cut to this size and handed out throughout the kingdom. This became the ruler.

Metric System: This was developed in France during the 1790s.

  • It is often called the International System of Units or SI.
  • It is a based on multiples of 10 so it is easy to convert from one unit to another.
  • The following prefixes are most commonly used in the metric system:

Prefix / Symbol / Value
kilo / k / 1000
hecto / h / 100
deka / d / 10
base unit (meter, liter, gram) / (m, L, g) / 1
deci / d / .1
centi / c / .01
milli / m / .001

Metric Length: The basic unit of length is the meter. To measure large distances, you would use kilometers (km). For items smaller than a meter, the centimeter (cm) or millimeter (mm) can be used. On a ruler it looks like this:

  • The numbered lines are cm
  • The smaller lines are mm
  • There are 10 mm in one cm
  • A decimal is used to show parts of a larger unit.

Weight: This is a measure of how much the force of gravity pulls on you. It is measured in pounds in the English System and Newtons in SI.

Mass: This is the amount of stuff that makes up an object. If you go to a different planet where the force of gravity is different than on Earth, your weight will change, but your mass will remain the same.

Metric Mass: The basic unit of mass is the gram. You can use a triple beam balance or an electronic balance to find mass.

Volume: This is the amount of space that an object takes up.

Metric Volume: The basic unit is the liter. Volume can also be reported in cubic centimeters. (cm3) 1mL = 1cm3

Volume of Liquids: can be measured using the graduated cylinder. Remember to read the number on the cylinder at the bottom of the meniscus (the curve that occurs at the upper surface of the liquid).

Volume of Regular Solids: If an object has a regular rectangular shape, you can find its volume by measuring the length, width, and height of the object and then multiplying. Volume = Length x Width x Height

Volume of Irregular Solids: If an object has an irregular shape, one way to find its volume it to use the displacement method. You see how much water is displaced by the object and that will tell you its volume. For example, if you drop a rock into a graduated cylinder, the water level will rise in an amount equal to the volume of the rock.

Density: is a property of matter. A pure substance will always have the same density regardless of its mass or volume because density is a ratio of mass to volume of an object. To calculate density, use the following formula: mass m

Density = volumeOR d = v

  • The density of water is 1g/cm3. If an object has greater density than water it will sink. If it has less density than water it will float.
  • Circle T Formula: Put the density formula into a circle T. Then cover the variable you are trying to solve for. This will show you the formula to use.
  • The circle T shows the following formulas:

m m

d = vv = dm = d x v