What is Matter? Section 17.1

Object comparison How are the following alike? – Rock – Paper clip – Book – Pencil – Box How do their sizes compare? Which would be the heaviest? Are these two the same?

Matter and Volume Matter is anything that has mass and takes up space (has volume).

Matter and Volume What are some examples of matter? Which glass is full? Which glass is empty? Is it truly empty?

Measuring Volume Liquid volume is usually measured in liters (L) or milliliters (mL). It can be measured using equipment such as: – Measuring cups – Beakers – Graduated cylinders – Pipets – Volumetric flasks Which one is used depends upon the precision needed in the measurement.

Measuring Volume Most liquids do not have a flat surface, but rather a curved surface, creating a meniscus at the top of the liquid. Most liquids with a meniscus curve downward, but there are a few, such as mercury, that curve upward.

Measuring Volume Always read the volume of a liquid at the flattest part of the meniscus – usually the bottom. Your line of sight is very important when reading the volume.

Measuring Solid Volume Solid volumes are expressed in cubic units, such as cm 3 or m 3. The volume of a cube or rectangular prism (box) is found using V = lwh. volume = length x width x height

Measuring Solid Volume What if the object has an irregular shape, not easily described geometrically? The displacement method can be used. In the example to the left, the water level rises about 3 mL because of the object, meaning it displaces 3 mL of water.

Measuring Solid Volume Since each mL of water takes up one cm 3 of space (1 mL = 1 cm 3 ), the irregular object must have a volume of about 3 cm 3. What is the volume of the toy dinosaur?

Mass Mass is a measure of the amount of matter in an object. It is usually measured in kilograms (kg), grams (g) or milligrams (mg), depending upon how massive the object is. This value does not depend upon the location of the object. Mass is measured using a balance.

Weight Weight is a measure of the gravitational force exerted on an object, so its location (on a particular planet, moon, or in deep space) can have an affect upon the object’s weight. Weight is measured using a spring scale. Units are newtons (N). websters-online-dictionary.org motherchildnutrition.org

Mass and Weight Comparing mass and weight and how they are affected by a change in gravity: realplayer videos\P029 Forces - Mass and weight.flv

Inertia The more massive an object is, the more it resists being moved. Inertia measures the tendency of an object to resist a change in motion. An object’s inertia increases as its mass increases. realplayer videos\How to demonstrate Newton's law of inertia Video « Wonder How To.flv media.ehs.uen.org

References: length.html length.html