Linked Questions

1
vote
2answers
98 views

Confused with heat as a form of energy [duplicate]

I have quite a simple question. Energy can be defined as capacity to do work. But I have read When energy is exchanged between thermodynamic systems by thermal interaction, the transfer of energy ...
0
votes
1answer
74 views

Is heat a form of energy or mode of transferring energy like work? [duplicate]

I have found somewhere that energy can be transferred by two modes, i.e., work and heat. Moreover there are many differences between heat and energy; like energy is a state function and heat is not. ...
85
votes
8answers
41k views

What Is Energy? Where did it come from?

The simplistic undergrad explanation aside, I've never really understood what energy really is. I've been told that it's something when converted from one kind of something to another kind, or does ...
26
votes
4answers
12k views

Is energy really conserved?

In high school I was taught energy was conserved. Then I learned that nuclear reactions allow energy to be converted into mass. Then I also heard that apparently energy can spontaneously appear in ...
13
votes
6answers
4k views

Why does a car engine not do work if the wheels don't slip?

I saw this mind boggling result that if the tires don't slip then the work done by an engine to move a car is zero. Why is this true? Moreover, what does this truly mean? Update: Sorry about not ...
2
votes
2answers
7k views

In an isothermal process how is the heat change non zero?

The temperature change in an isothermal process is zero. As a result (if the system is made of an ideal gas) the change in internal energy must also be zero. I don't want to consult the equations. I'm ...
1
vote
2answers
10k views

Difference between heat and work

According to the Kinetic Theory of Matter, temperature is nothing but a measure of the kinetic energy of matter. My textbook says that the change in internal energy of a system is the heat gained plus ...
4
votes
3answers
168 views

What exactly is temperature? [duplicate]

I'm trying to have a really deep understanding of quantum physics and so I went back to what is blackbody radiation until suddenly I realized that my understanding of temperature is that of... well, ...
3
votes
2answers
854 views

Intuition behind the concept of heat

Even if elementary, I'm afraid I am still not comfortable with the concept of heat. I can picture heat as some kind of incompressible fluid that is transferred from a body to another in such a way ...
2
votes
4answers
346 views

Solids: is energy expended in some fashion by, say, a table to keep the top from sinking down against gravity?

A friend and I were discussing this, and couldn't decide. Since it takes energy to physically raise something up above the planet's surface, does it continue to require energy in order to keep it ...
0
votes
0answers
332 views

Definition and Measurment of Energy and Heat in Thermodynamics

The concept of work is clear from mechanics, where $dW=F\cdot dx$, leading to $dW=PdV$. Also different forms of energy are defined in mechanics, e.g., $E=\frac{1}{2}m v^2$, etc. How are the energy and ...