11.2 Particulate Model for Solids, Liquids and Gases A block of ice Solid molecules have a restricted motion = Solid A beaker of boiling water Gas molecules are able to move at extremely high speed = Gas A beaker of warm water liquid molecules have greater mobility = Liquid States of Matter Solid * In solids, the molecules are arranged close together in a regular pattern * Strong attractive intermolecular forces hold the molecules in position so they have definite shape and volume * They can only vibrate in their fixed positions Liquid * In liquids, the molecules are not arranged in a regular pattern and are slightly further apart then those in solids * The attractive intermolecular forces are not very strong. Thus, the molecules are able to move among one another, giving liquids its definite volume but not a definite shape. Gases * In gases, the molecules are widely spaced. Intermolecular forces are negligible * The molecules move about randomly with high speeds, colliding with the walls of the container, occupying any available space. Research on *phase changes for water* Heating curve (Please!!!!!!
The slower molecules gain more thermal energy and collide with other molecules in the cooler object. This process continues until heat energy from the warmer object spreads throughout the cooler object. Some substances conduct heat more easily than others. Solids are better conductor than liquids and liquids are better conductor than gases. Metals are very good conductors of heat, while air is very poor conductor of heat.
Also a larger concentration gradient produces a faster diffusion, and smaller molecules diffuse more rapidly than larger molecules. If you imagine a crystal of dye in a beaker of water, the crystal would be the solute because it is the dissolvable substance, and the water is the solvent because it’s what the solute dissolves into and there tends to be more of it, both of these form together to create a solution. If you look at the colour of the water just next to the crystal it would be
The amount of air pressure depends on how often these particles collide. For a balloon to fly, the air pressure needs to be high, at least as high as the outside air pressure otherwise it would crush it. There are a few ways to increase air pressure including adding more gas particles to increase the frequency of collisions or raising the temperature of the air to speed up the particles which in turn would result in more collisions and greater air pressure. Since it is important that the air is heated up, it also helps if the outside air is cooler so that there does not have to be as many gas particles to create the same high air pressure. Overall, buoyancy and air pressure
First, the wave, like all sound, is a longitudinal pressure wave. In a longitudinal wave, movement of the points in the wave is parallel to the direction the wave travels. It is the kind of motion if it pushed and pulled one end of a stretched Slinky. Most illustrations, though, depict sound as a transverse wave, which is what would see if it rapidly moved one end of the Slinky up and down. This is simply because transverse waves are easier to visualize than longitudinal waves.
Longitudinal wave The vibrations of the object set particles in the surrounding medium in vibrational motion, thus transporting energy through the medium. For a sound wave traveling through air, the vibrations of the particles are best described as longitudinal. Longitudinal waves are waves in which the motion of the individual particles of the medium is in a direction that is parallel to the direction of energy transport. Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. As the vibrating string moves in the forward direction, it begins to push upon surrounding air molecules, moving them to the right towards their nearest neighbor.
Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. * the density of a liquid is usually close to that of a solid, and much higher than in a gas. Therefore, liquid and solid are both termed condensed matter STRESS * A stress is expressed as a quotient of a force divided by an area. There are many kinds of stress.
The bigger the mass of an object, the less effect the force applied has on it. The effect of a 1kN force on a football would be much greater than on a bowling ball. The difference in acceleration is due to the difference in their masses. The Second Law gives us an exact relationship between force, mass, and acceleration. It can be expressed as a mathematical equation: or FORCE = MASS X ACCELERATION 3.
A sound wave is a type of pressure wave caused by the vibration of an object in a conductive medium such as air. When the object vibrates, it sends a series of waves that can be interpreted as sound. For example, when someone hits a drum, causes the membrane of the drum to vibrate, and vibration is transmitted through the air, where it can reach the ear of a listener. Not all sound waves are in the audible range. Humans hear about 12 Hz to 20 kHz, which means that sounds above and below this range usually cannot be heard, and some animals can hear in the upper and lower ranges.
To determine psub and pdesign, since A* = Athroat, use the subsonic and supersonic Mach numbers corresponding to isentropic flow with area ratio Aexit/Athroat: where Masub and Madesign are the subsonic and supersonic solutions, respectively, of Figure 1. CD nozzle theory For back pressures between psub and pdesign there are shocks inside the nozzle or in the exit jet. At pshock-exit a shock occurs at the exit plane. This value can be computed by assuming a normal shock with upstream values pdesign and Madesign and downstream pressure pshock-exit: The maximum mass flow rate occurs when the throat is sonic: Where, p = pressure; p0 = total pressure; Ma = Mach number; Γ = ratio of specific heat