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# Tag Archives: Thermodynamics

## Path dependence of Thermodynamic Variables

In NCERT TEXT BOOK it is written that
Since U is a state variable, ΔU depends only on the initial and final states and not on the path taken by the gas to go from one to the other. However, ΔQ and ΔW will, in general, depend on the path taken to go from the initial to final states. From the First Law of Thermodynamics,it is clear that the combination ΔQ – ΔW, is however, path independent.

ΔQ and ΔW will, in general, depend on the path taken ??andΔQ – ΔW, is however, path independent.
explain?? how??

## INTENSIVE VARIABLES AND EXTENSIVE VARIABLES

A thermodynamic variable may be intensive or extensive.

What are intensive variables?

The variables which are independent of size or amount of substance are called intensive variables.

Example: Density is an intensive variable. (because it does not depend on the amount of that substance)

What are extensive variables?

The variables which depend on the size or amount of the substance are called extensive variables. It is additive for independent, noninteracting subsystems

Example: Mass and volume are extensive variables. (Because they are directly measuring the amount of substance)

## Specific Heat capacity and Molar specific Heat capacity

“how to calculate molar the heat capacity of a gas
given cp and cv of the gas?”

Specific heat capacity of a substance is the quantity of heat required to raise the temperature of 1g of that substance through 1oC. It can be measured at constant pressure (Cp) and at constant volume (Cv).

Molar heat capacity of a substance is the quantity of heat required to raise the temperature of 1 mole of the substance by 1oC.

Molar heat capacity = Specific heat capacity × Molecular weight,

i.e.,

Cv = cv × M and Cp = cp × M.

## One-dimensional motion

In this tutorial we begin to explore ideas of velocity and acceleration. We do exciting things like throw things off cliffs (far safer on paper than in real life) and see how high a ball will fly in the air.

## Two-dimensional motion

You understand velocity and acceleration well in one-dimension. Now we can explore scenarios that are even more fun. With a little bit of trigonometry (you might want to review your basic trig, especially what sin and cos are), we can think about whether a baseball can clear the “green monster” at Fenway Park.

## Forces and Newton’s laws of motion

This is the meat of much of classical physics. We think about what a force is and how Newton changed the world’s (and possibly your) view of how reality works.

## Work and energy

“Energy” is a word that’s used a lot. Here, you’ll learn about how it’s one of the most useful concepts in physics. Along the way, we’ll talk about work, kinetic energy, potential energy, conservation of energy, and mechanical advantage.

## Impacts and linear momentum

Momentum ties velocity and mass into one quantity. It might not be obvious why this is useful, but momentum has this cool property where the total amount of it never changes. This is called the conservation of momentum, and we can use it to analyze collisions and other interactions. Bam!

## Moments, torque, and angular momentum

Everything you’ve learned about motion, forces, energy, and momentum can be reused to analyze rotating objects. There are some differences, though. Here, you’ll learn about rotational motion, moments, torque, and angular momentum.

## Gravitation

Gravity is the force of attraction between masses. It’s the thing that pulls you down to earth. Here, you’ll learn precise meanings of the words mass and weight, and you’ll also learn how gravity affects falling near earth and orbits in space.

## Oscillatory motion

Pendulums. Slinkies. You when you have to use the bathroom but it is occupied. These all go back and forth over and over and over again. This tutorial explores this type of motion.

## Fluids

Atmospheric pressure is like an invisible friend who is always squeezing you with a big hug. Learn more about pressure, buoyant force, and flowing fluid so you can appreciate the sometimes invisible, but crucial, effect they have on us and the world around us.

## Thermodynamics

Heat can be useful, but it can also be annoying. Understanding heat and the flow of heat allows us to build heat sinks that prevent our computers from overheating, build better engines, and prevent freeway overpasses from cracking.

## Electric charge, electric force, and voltage

Electric forces hold together the atoms and molecules in your eyes which allow you to read this sentence. Take a moment and learn about the force that holds our bodies together.

## Circuits

Circuits make computers, digital cameras, and video games possible. Circuits are driving an unprecedented rate of change in how we live. In this topic you’ll learn about the physics behind the electronic devices we use.

## Magnetic forces and magnetic fields

The magnetic field of the Earth shields us from harmful radiation from the Sun. Magnetic fields also allow us to diagnose medical problems using an MRI. In this topic you’ll learn about the force and field that makes this possible.

## Magnetic flux and Faraday’s law

Faraday’s law is how we get electrical power from most power plants and hydroelectric dams. Learn how magnetic flux allows us to turn the mechanical energy of falling water through a dam into electrical energy.

## Mechanical waves and sound

Waves are responsible for basically every form of communication we use. Whether you’re talking out loud, texting on your phone, or waving to someone in a crowd there’s going to be a wave transmitting information. Learn about the basics of waves in this topic, then learn more about light waves in the topics below.

## Light waves

Light can seem mysterious. What is light made out of? What causes color? How do 3D movies work? Learn about some of the mysterious properties of light in these tutorials.

## Geometric optics

Light waves can be bent and reflected to form new and sometimes altered images. Understanding how light rays can be manipulated allows us to create better contact lenses, fiber optic cables, and high powered telescopes.

## Special relativity (sneak peek)

Think you know about time and space? Think again. Einstein basically did a pile driver on all our brains when he came up with his theory of special relativity. Note: This topic is under construction. More videos and materials will be added soon.

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