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ELASTICITY AND FLUID PHYSICS. Elisha Faye M. Yuipco. What Matters to a Physicist. Matter- is the substance of which all objects are made. It can be changed into energy and energy into matter.
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ELASTICITY AND FLUID PHYSICS Elisha Faye M. Yuipco
What Matters to a Physicist • Matter- is the substance of which all objects are made. It can be changed into energy and energy into matter. • Inertia-is an object’s resistance to a change in its state of motion. An object that is at rest tends to remain at rest due to inertia. • Mass- is a measure of inertia. -also the source of gravitation , a force of attraction between two objects.
Structure of Matter • An atom is made up of three Particles: -Protons -Neutrons -Electrons Protons and Neutrons, carry most of the atom’s mass, are composed of point-like units called quark.
Diameter of an Atom: 0.1 to 0.5 nanometer. • Nanometer- is a billionth of a meter, or 1/25,400,000 inch. • Protons have a positive charge, and neutrons are electrically neutral so the nucleus as whole is positively charged. Electrons are negatively charged. Opposite charges attract, an electric force tends to keep the electrons in place. • Electrons whirl around he nucleus in layers called electron shells.
The General States of Matter Matter can change from one state to another. When this occurs, the appearance of the matter may change drastically. However, its chemical composition remains the same. 3 Phases of Matter • Solid • Liquid • Gas
The Physicists’ Other State of Matter In the 1990’s, scientists identified 4 states: 1. Plasmas- are gas like substances in which some or all atoms have a lost at least one electron, leaving a mixture of free electrons and positively charged ions. 2. Super Fluids- are liquids that flow without resistance. As a result, they will pass through the pores of a container.
3. Super Conductors- are solids in which electrons move freely. An electric current in a superconductor can flow forever without the help of an external supply. Many metals are superconductors at temperatures within a few degrees of absolute zero. 4. Bose-Einstein Condensates- are clusters of millions of atoms that merge under conditions of extreme cold.
Unusual Forms of Matter • Scientists have discovered a unusual form of matter called antimatter. • Physicists can convert energy into matter with devices called particle accelarators. • When subatomic particles collide at highs speeds they create new particles. • Antimatter Particles are rare and last only until the encounter matter and are destroyed.
DARK MATTER • More than 99% of the visible universe is made up of the 2 lightest kinds of atoms, hydrogen and helium. • The most of the matter in the universe is invisible dark matter. • Matter and Fields The Point-like particles- the smallest particles of matter; it has no size at all. This particles serves as “centers of force” that attract or repel one another through fields of force.
The positively charged quarks that make up a proton attract an electron by means of an electromagnetic field. • Electromagnetic field- is composed of energy particles knows as photons. One charged matter particle attracts or repels another by emitting a photon, which other absorbs.
Density and specific gravity • Density- is the mass; the amount of water; in a unit volume of any substance. • Chemists measure the density of a solution to determine the concentration of a substance in that solution. They calculate the molecular weight of a gas from its density. • The density of a substance equals its mass divided by its volume. Density is commonly expressed in grams per milliliter or pounds per cubic foot.
Density in solids • To determine the density of a regularly shaped solid, first measure the object’s mass- that is, weigh the object. Next measure, one or more of the object’s dimensions and calculate its volume from a mathematical formula for objects of that shape. Then divide the mass by the volume.
DENSITY IN GASES • To determine the mass of a gas, first weigh an empty container. Next, fill the container with the gas and weigh it again. Then subtract the first measurement from the second. To determine the volume of the container, measure the amount of water that the container hold.
SPEcific gravity • The specific gravity of a substance is related to its density. Specific gravity equals the mass of a given volume of the substance divided by the mass of an equal volume of water. To determine the specific gravity of a substance, divide the density of the substance by the density of water at either 4 degree celsius (39F) or 20 degree celsius (68F)
EXAMPLE: • How many kilograms of air are in your room? Assume your room is 10m X10m 3.0 m. The density of air at sea level is about 1.2kg/m3. Given volume of the room V 10mX10mX3.0m=300m3 density of the air at sea level D 1.2kg/m3 Solution M= DV = 1.2kg/m3(300m3)=360kg