Mr. Bouyer

Day 1 | Day 2 | Day 3 | Day 4 | Lab 1 | Lab 2 | Vocabulary Test

Matter Inertia Mass Weight Gravity	Newton Volume Cubic decimeter Density Factor-label	Universe Galaxy Solar System Big Bang Theory Earth

Properties of matter:

Inertia - the resistance of an object to changes in motion.
• If an object is at rest, a force is needed to make it move.
• If an object is moving, a force is needed to slow it.

Mass - the amount of matter in an object.

• Mass can also be defined as a measure of the inertia of an object.
• The mass of an object is constant. Mass does not change as an object is moved from one place to another.
• The SI unit of mass is the gram (g) or kilogram (kg).
  • The Sun has a mass of 1.9891 X 10 ³⁰ kg.
  • The Earth has a mass of 5.976 X 10 ²⁴ kg.

Weight - a measure of the pull of gravity on an object.

• All objects exert a gravitational attraction on other objects.
  • Gravity is the weakest of the natural forces.
  • The greater the mass of an object, the greater the gravitational force.
  • The pull of gravity between objects decreases as the distance between the centers of the objects increases.
  • For this reason, the weight of an object is not constant. However, an object orbiting the earth is not weightless. There is still an attraction between the object and Earth.
• The SI unit of weight is the Newton (N). One Newton = 1 kg . m / s ²
• Weight is calculated using the equation: W = mg
  The m represents the mass of the object and the g represents the acceleration of gravity.

• Near the surface of the Earth, the acceleration of gravity is 9.8 meters per second per second - 9.8 m/s².

Volume - the amount of space an object takes up.

• The SI unit for volume is the liter (L).
• The volume of regular solids can be calculated with equations based on the shape of the solid. These equations are based on units of length. Since a regular solid is a 3-dimensional object, the answer in any of these equations will have "cubic" units. The cubic decimeter, dm³, is equal in volume to the liter.

  The language of science reads cubic units like these as "cubic decimeters", not "decimeters cubed".

Test Your Concept Understanding: Write a paragraph explaining the difference between mass and weight. Calculate your weight: Convert your "weight" in pounds to kilograms. (Hint: use 1 pound = 0.5 kg) Use the weight equation to calculate your weight in Newtons. A rectangular solid measures 5cm, by 10cm, by 2cm. Show how to calculate its volume. Show how to calculate the volume of a sphere whose diameter is 15 cm. If you need an equation, use this website. Would the acceleration of gravity on the Moon be different from the Earth? If so, how? Two sealed jars are identical except one has air in it and the other has had all the air removed. Do the two jars have the same mass? Two identical empty jars and lids are sitting on a table. You pick up a lid and tightly close one jar. You do the same with the other jar, except before closing it you put two bumblebees in the jar. The bees fly around inside, never touching the jar glass. How will the mass of the two jars compare when placed on a scale?

Day 2

What is the density of water?

Properties of matter continued:

Density - mass per unit of volume.
• Every type of matter has a certain density. Because of this, density can be used to identify types of matter.
• Density is calculated with the equation:
  D = m / v

  The m represents the mass of an object and the v represents the volume of the object.

• Density is most often expressed in grams per cubic centimeter.

  The density of water is 1g/cm³.

Lab #1


Specific gravity: a ratio of the mass of a substance to the mass of an equal volume of water.

• Notice that specific gravity is a ratio, one of the few number expressions in science that has no units.
• The density of water is 1g/cm³. The density of iron is 7.9g/cm³. If we set up a ratio of the mass of 1cm³ of iron to the mass of 1cm³ of water, we get 7.9 :1. The specific gravity of iron is 7.9.

Study this page about the factor-label method:

Homework Assignment 032:
This assignment must be turned in by the beginning of class tomorrow to receive credit.
Scoring criteria

1. Using density, write a paragraph explaining the picture at the top of today's page.
2. This periodic table is linked at the bottom of each Physical Science Class 9-weeks page. Use it to find the density of chlorine, gold, and uranium.
3. What is the specific gravity of water, hydrogen, lithium, and carbon?
4. Use the factor-label method to make the following conversions:
   1. A density of 250 grams per liter to g/cm³.
   2. 6245 seconds to hours.
   3. 200 ounces to pounds. (16 ounces = 1 pound)
   4. 12000 grams to kilograms.
   5. A density of 2 tons per megaliter to g/cm³. (1 pound = 454 grams)
5. Given: one gallon of water weighs 8.34 pounds; one cubic foot of water weighs 62.4 pounds. Use factor-label to answer the following:
   1. What is the weight of 6.5 gallons of water?
   2. How many cubic feet of water are in question a?

Research links:

• The specific gravity of minerals - The Mineral Gallery
• Antimatter - European Organization for Nuclear Research

Physical Science

Objects in space are not weightless! Weight is caused by gravity and objects in space are never free of gravity.
Objects orbiting the Earth are actually being pulled toward the Earth by gravity. Since these objects are falling at the same rate, they appear to be floating.

The density of water is one gram per cubic centimeter - 1g/cm³
This accepted value for the density of water is measured at 4 ^oC, when water is most dense.