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Explore the fundamentals of matter in this unit. Learn about volume, mass, and weight. Discover how to measure volume and mass, distinguish between weight and mass, and understand gravity and inertia. Dive into the math of science and compare properties of liquids and solids.
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What is Matter? Mod.H Unit 1 L. 1
Matter is… • Anything that has mass and occupies space
ALL matter have twobasic properties… • Volume, and • Mass
Property #1 -Volume • Allmatter has volume. • How did we prove that air has volume? • Volumes of liquids are measured with what units? • Units for Volume of solids?
Volumes … • Can the volume of a gas be measured with a graduated cylinder? • So how can the volume of a gas be measured?
Find out! Write in your ntbk. What is AIR composed of? Is sound matter? What about light?
Math in Science! Complete in your ntbk. • A book has a length of 25 cm, a width of 18cm and a height of 4 cm. What is its volume? 2. a) What is the width of a suitcase with a length of 95 cm, a depth of 20 cm and a volume of 66500 cm3? b) What is the volume in m3?
Comparing liquid and solid Volumes • Remember: 1 mL = 1cm3 • Equipment: • Liquids are measured using a …? • Solids are measured using a … ? 2 Ways: • Displacement - Object itself occupies space • Capacity - Object has space within it
Property # 2 - Mass • Allmatter has mass. • Is air matter? • Do you think that air has mass? Proof?
Mass vs. Weight • Weightis NOT mass • Weight is a measure of gravitational force acting on a mass • Measured with a Spring Scale in Newtons
Gravity • Gravity is the force of attraction between objects • Gravity depends on • the amount of mass, and • the distance between masses
Newton’s Law of Universal Gravitation All objects in the universe attract each other through Gravitational pull The size of the force depends on: • The sizes(masses) of the objects, and • The distance between them.
Now, your Weight! • The Earth is very large and pulls on you. This pull decreases as you get further from the Earth. • So your weight depends on how close you are to the center of the Earth.
Comparing weights • A brick and a sponge: • Same size (volume)! • The brick weighs more because it is pulled down to Earth more (it has more mass) than the sponge • Weight decreases the further away you go from the Earth’s center
So… ! • Your weight depends on your mass PLUS how close you are to the Earth’s center. • Weight is measured in Newton's (N) or (kN - kiloNewtons) • 1 N≈Wt of a 100g
Weight is calculated by: Taking the mass of something and multiplying it by the gravity of the planet (9.8 or ≈ 10 m/s2) called acceleration due to gravity (g). Weight(Force) = mass x gravity W = mg (units=gm /s2) or F(weight) = m•a
Calculate! • What is the weight in newtons, of a set of text books that have a total mass of 3kg? • Convert to g • 3kg x 1000g/1kg = 3000 g • Then, Convert to N • 3000g x 1N/100g = 30N The book weighs ≈30N • F(w) = 30 kg • 9.8 m/s2 = 294 N
NOTE!! • The greater the mass of an object, the greater the gravitational force on the object and the greater the weight will be. • Mass stays the same for an object even when increased or decreased gravitational forces change the weight of the object.
Weight on the moon…. The moon is ≈1/6 the size of the Earth On the moon, an object weighs ≈1/6its weight on the Earth 72 N on earth = ? On the moon 72 N x 1 = 12 N on the moon 1 6 If mass = 50kg on earth = ? On moon Stays the same! = 50kg on moon
Density • Is a measure of amount of mass per unit volume • Is the same for a given substance no matter how much you have • Density = Mass Volume • D = M / V • Units: g/cm3 g/mL
Water has a density of ≈1 g/mL. • Thus, objects with density greater than 1 g/mL sink in water. • Objects with density less than 1 g/mL float in water.
HMWK: Math in Science 2 Find the following: • Mass and weight of object on the Moon, if on Earth a) its mass = 156 g, b) its weight = 204N, • Weight of object on the Earth if on the moon it weighs: a) 33 N
Answers 1 a) 156g .Mass doesn’t change! b) 204N x 1/6 = 34 N 2. a) 33N x 6 = 198 N
Mass is a measure of Inertia • Think “teenagers”!!!! • When something is at rest, it tends to stay at rest! • The larger the mass, the more inertia the matter has
Inertia is … • The tendency of an object to resist any change in motion. • The larger the mass, the harder it is to start a stationary object, or stop a moving object
HMWK • Guided Practice: Write a paragraph or make a small Graphic explaining : • How the weight of an object can change even though its mass does not change.
HMWK - in your Ntbk • Answer these questions: 1. What are the two basic properties of ALL matter? • How is volume measured? How is mass measured? • Analyze. Do objects with large masses have large weights? Explain your reasoning.