Thermodynamics and Statistical Mechanics

If the ice is right at or close to the melting point temperature at ambient pressure, the pressure of a nickel will cause ice to melt and allow the nickel to penetrate into the ice, displacing the melted water as it goes.

1) In general, the second laws states that all energy in the universe will head towards its lowest state. Another way of stating it is "the universe will tend towards maximum entropy" or "heat cannot of itself flow from a colder body to a warmer body."

2) All systems try to achieve a state of minimum energy and maximum randomness. any amt. of work can be converted to heat. but heat can only partially be converted to work.

The internal energy change of the system can be calculated by subtracting the work done by the system from the heat added to the system. In this case, the internal energy change is ΔU = Q - W = 850 J - 382 J = 468 J. Therefore, the internal energy of the system increases by 468 Joules.

The ideal gas law is called ideal because it is a mathematical idealization and not meant to be exactly descriptive and any real gas.

It is famous because it does an excellent job of describing real gasses and it is something to which you can use with a real gas.

The ideal gas law is used very often because it works the same for all gasses once the temperature is high enough and the gas dilute enough. One does not need to know what kind of gas one is describing in those circumstances and so it saves having to keep track of different gas laws and properties for many different types of atoms and molecules. The trick is to know that for any particular gas, you are at a high enough temperature and low enough pressure. It turns out that normal temperatures and pressures that humans live with is already good enough for many common gasses, like those that make up air and methane and butane that we burn for fuel and many others.

If you want to know the ideal gas equation, one common way of stating it is as follows.

PV=nRT.

P is pressure. V is volume, T is (absolute) temperature, n is the number of gas particles (measured as moles in chemistry) and R is the universal gas constant. It is called universal because it is the same constant for all gasses.

Those are the basic facts. Now, here is a bit more about it.

The ideal gas law works well when a gas has a very low density and a high enough temperature that the forces between gas particles are insignificant. The trick is that you need to know the temperatures and the densities (or pressures) where it starts working. The accuracy of the comparison between the ideal gas law and the behavior of a real gas depend on staying at the higher temperatures and lower densities.

For all neutral atoms and molecules that form gasses, there is an weak attractive force when they are far apart and a strong repulsive force when they get very close. In between, complicated things happen which are different for different types of atoms and molecules. In any case, that is why the gas density has to be low, so these interactions between gas particles are very rare.

What is really amazing is that if you can get a material to form a gas, then it pretty much follows the ideal gas law for all the temperatures and pressures and volumes that it takes as long as you stay away from the temperatures and pressures where it will convert back to its original condensed form which is usually a liquid. Even water follows the gas law when it is in the form of water vapor or steam and water turns out to be one of the types of materials that are a little uncooperative.

As an aside, it is worth mentioning that many materials will not form a gas because if they are heated to the point of vaporizing, they will undergo chemical change. Large molecules in particular tend to break apart before they can be heated enough that the temperature can supply enough energy to separate the molecules from each other. After the chemical change occurs, then the new chemical will often easily form a gas.

The maximum efficiency of the carnot engine only depends on two factors:

1 - The temperature of the hot reservoir (TH)

2 - The temperature of the cold reservoir (TC)

And is given by (TH - TC) / TH « or » 1 - TC / TH So by that we can see the maximum efficiency (100%) would be when the difference of temperatures between the two reservoirs is infinite.

Thermodynamics is the branch of physics that deals with the relationships between heat, work, and energy. It describes how energy is transformed from one form to another and how it flows within a system. The laws of thermodynamics govern these energy transformations and provide a framework for understanding the behavior of systems.

The first law of thermodynamics states that in any thermodynamic process, when heat Q is added to a system, this energy appears as an increase in the internal energy stored in the system plus the work done by the system on it's surroundings.

or to shorten that, energy can neither be created nor destroyed, but it can change from one form to another

i hope this helped ^^

Equilibrium and maximum entropy (for the universe).

The name of this phenomenon is conduction.

At thermodynamic equilibrium the dynamic processes for changes in a system have reached a steady state (not changing with time) where temperature has stabilized to a constant, no heat is being exchanged, no work is occurring, composition is constant (reactants are being converted to products at the same rate that the products are converting back to the reactants), pressure is constant, if there is more than one phase, movement between the phases is balanced (for example evaporation and condensation are occurring at the same rate), and there are no concentration gradients.

The wedge on a drill is found at the tip of the drill bit. It is designed to create a splitting action, allowing the drill to penetrate materials by forcing them apart as it rotates. This design helps to create holes in various surfaces with minimal effort.

Yes, the Gibbs free energy equation can be used to determine the thermodynamic feasibility of a reaction as well as to calculate the equilibrium constant based on measurements at different temperatures. The equation relates the change in Gibbs free energy to the change in enthalpy, entropy, and temperature.

Thermodynamics deals with the equilibrium states of matter and can be extended to define the driving forces for changes from one equilibrium state to another when a system is subjected to external changes. When a system changes from one equilibrium state to another, thermodynamics also helps to determine the quantity of work & heat interactions according the the path taken to transition from the initial state to the final state.

Heat is the movement of energy from one system to another due to a temperature gradient. It is frequently confused with "internal energy" or "thermal energy". We think of a system as being "hot" when it has a lot of internal energy that it can transfer to another system which is at a lower temperature. When the energy moves, it is called heat. As an analogy, we can compare heat to rain. When the water is in motion from the clouds to the ground, we call it rain. The rain moves due to a potential energy gradient between the clouds and the ground due to gravity. When the water is tied up in the clouds, it isn't rain. When it is pooling on the ground it isn't rain. It is only rain when it is moving between the two. Likewise heat is the energy MOVING from one system to another. You can heat a system up by transferring energy into it via heat - or you can add the energy to it via doing work on it. Once the energy is added, the internal energy has increased - but it doesn't have more "heat".

Buckle up 'cause the NASA mechanical engineer has his hands full. Both of them! The mechanical engineer might be called an "applied physicist" because he takes the principles of physics and applies them to mechanical systems. Let's check it out. Rockets, space stations, satellites and stuff like that are all mechanical structures. Someone has to figure out what is wanted, what is needed, and what is possible. They'll also need to figure out what will have to be "bridged" and "created" or "invented" using the most current materials, methods and manufacturing processes to make it happen. They reach into the future to adapt innovative and newly appearing materials and ideas as well. These thinkers and problem solvers will be looking at everything from, say, the overall size, shape and mass of a modular Skylab addition to the individual fasteners, welding techniques or machining that will be used to build it and keep it together. Everything in between will also be looked over closely. One NASA engineer will be looking at a module, and another will be looking at how it couples to other modules. Still another will be thinking about what fixtures and machinery will be needed to handle the piece on the ground, and also up in space to throw it out of the ascent vehicle and position it for attachment. Senior engineers who have "been there and done that" will oversee sections of the projects, and those in work groups will report to them. Anyone in space is riding in a mechanically engineered vehicle or on a mechanically engineered platform. He's breathing air from a mechanically engineered air system, and drinking and eating stuff held in mechanically engineered reservoirs or compartments. He cleans himself and gets rid of waste in mechanically engineered facilities. Think about what you do in a day and imagine doing it in a box about the size of a walk-in closet. That closet up there displays the best the mechanical engineers can come up with. NASA engineers use all their education to pull off the things they do. They're all math minors (or physics minors, or both - or even double majors!) 'cause they flew through the Calculus and applied it to stress and strain problems, thermodynamics, fluid mechanics and a whole bunch of other stuff Newton could only dream about. There are lots of things "hidden" in mechanical engineering. Robotics. Nanotechnology. Composites (with chemists). Oh, and how do you suppose we figure out about how craft will behave in space? Orbital mechanics is really mechanical engineering. If you're considering mechanical engineering, math and physics pave the way. Know that up front. These are the heart and soul or "backbone" of this branch of engineering. It's a science. And only thinkers need apply. Problem solvers. Outside-the-box operators. But it's something you can do if you want it. Betcha. Start now. Come to think of it, by asking the question, you've already started. Step on up. See it happening. Go for it. Never let up. One class at a time, one semester at a time. The door is open. Step through. Got links if you want 'em. Look below.

Quasi static process - doesn't really exist except in theory. It is a thermodynamic process going infinitely slow. The best example is if you had air at 1C inside a cryogenic thermos and you had add outside the thermos at 1.00000000000001C. The point is is the air inside the thermos would eventually warm up to the slightly warmer air outside the container, but it would take a long long time.

In a practical heat engine, heat is generated by burning a fuel, work is extracted from this heat resulting in the working fluid cooling, and heat is then rejected at the lower temperature. As you must know, in an internal combustion engine heat is rejected both in the engine cooling system and the exhaust.

In a power plant, using water/steam as the working fluid in a closed cycle, there are four phases in the cycle: 1. Water is pumped at high pressure into a steam raising unit (boiler) 2. Heat from the fuel, be it coal, oil, gas, or nuclear, is added to the water causing it to become steam 3. the steam is expanded through a turbine doing work, that is driving the generator 4. the steam is condensed back to water using external cooling water. This is called the Rankine cycle. At stage 4 heat is being rejected into the external cooling water, and this heat is lost. It is minimised by running the condenser under vacuum so that steam at less than 100 celsius can still do work, and the final turbine discharge temperature is as low as 30C. Theoretically the efficiency of such a cycle is maximised by making the steam to the turbine as hot as material constraints allows, and the condenser vacuum as low as the local cooling water temperature will allow. The maximum practical efficiency of such a plant is about 42 percent, meaning that 58 percent of the heat from the fuel is rejected. For a PWR nuclear plant the steam temperature is much lower and the cycle efficiency is less, more like 30 percent.

I hope this enables you to see why in a practical heat engine there must be heat rejection. There are several entries in Wikipedia for further reading, see 'Heat Engines' first.

activation energy. This is the minimum amount of energy needed for the reactants to transform into products. Once the activation energy is surpassed, the reaction can proceed to completion.

First let's define what "heat" really is. It's the average kinetic energy (KE) of the atoms and molecules of the object that is heated. The higher the KE the higher the heat.

So when heat transfers, say from a cook stove into the bottom of a frying pan, the high KE of the stove grill atoms and molecule literally smashes into the atoms and molecules of the frying pan and that gets the pan particles into moving faster resulting in the higher KE (higher heat) in the pan.

Which is why you can get your bacon and eggs for breakfast.

That is exactly what it means - however there is still the question of rate of reaction and equilibrium.

As an example - thermodynamics favor the conversion of diamond back to something more like graphite at normal room conditions, but the process is so slow that no one will observe the change within their mortal lifetime (nor will their great-great-great-great grandchildren). The point is that the rate of reduction of N2 to NH3 is not especially fast.

There are also competing reactions and the tendency of the reverse reaction to occur - which becomes pronounced as equilibrium is approached.

In a non-stable equilibrium state in engineering thermodynamics, the internal energy of the system is constantly changing as the system is not in a state of static equilibrium. Energy is being continuously exchanged with the surroundings, leading to fluctuations in internal energy. The system is not able to maintain a constant internal energy value as it is constantly responding to external influences.

According to the first law of thermodynamics energy can neither be created nor be destroyed and any change in energy of a system is accounted for by work done.

The work-energy relationship is the foundation on which all engines and motors operate, including the human engine. Energy gets converted into other forms of energy or it gets used to do work.

Many ways, and it depends on the type of ship. A large ship will benefit from thermodynamic analysis of the HVAC system (especially if it is a refrigerated cargo ship); smaller ships will also benefit from this as well.

In addition, most thermodynamic solvers on the market will also do fluid solutions, which is obviously helpful for a ship.

The process is called isothermal expansion. This occurs when a gas expands and cools down while maintaining a constant pressure.