# Thermodynamics Conceptual Question

• fridakahlo
In summary, the conversation discusses the relationship between adding energy to a system and its resulting temperature change. It also mentions equations related to volume and internal energy. The question posed is whether adding energy to a system would increase its internal energy and subsequently its temperature. The answer is yes, as long as there is no change in the system's kinetic or potential energy.
fridakahlo
Hi! I'm new to the forums, so I apologize in advance if I'm posting my question in the wrong section. I'm studying thermodynamics right now, and I came across this sentence from my book:

## Homework Statement

"When energy is added to a system and there is no change in the kinetic or potential energy of the system, the temperature of the system usually rises."

## Homework Equations

Volume is proportional to Temperature
Internal Energy= Bond energy + Thermal energy

## The Attempt at a Solution

I'm confused. Wouldn't adding energy to the system increase the system's internal energy (therefore inc. its kinetic/potential energy)? The only way I can see the above statement to be true is if there was an increase in volume of the system. And since volume is proportional to temperature, the temperature of the system would also rise. Are my assumptions correct or am I overthinking it?

fridakahlo said:
Hi! I'm new to the forums, so I apologize in advance if I'm posting my question in the wrong section. I'm studying thermodynamics right now, and I came across this sentence from my book:

## Homework Statement

"When energy is added to a system and there is no change in the kinetic or potential energy of the system, the temperature of the system usually rises."

## Homework Equations

Volume is proportional to Temperature
Internal Energy= Bond energy + Thermal energy

## The Attempt at a Solution

I'm confused. Wouldn't adding energy to the system increase the system's internal energy (therefore inc. its kinetic/potential energy)? The only way I can see the above statement to be true is if there was an increase in volume of the system. And since volume is proportional to temperature, the temperature of the system would also rise. Are my assumptions correct or am I overthinking it?
In this context, when they are talking about kinetic or potential energy, they are referring to the macroscale. The potential energy they are referring to is gravitational potential energy, and the kinetic energy they are referring to is based on the mass average velocity over each small localized volume including a huge number of molecules.

Your interpretation that the internal energy increases and the temperature increases is totally correct.

Thanks Chestermiller!

Last edited:

## 1. What is thermodynamics?

Thermodynamics is the branch of science that deals with the study of energy and its transformation from one form to another.

## 2. What is the first law of thermodynamics?

The first law of thermodynamics is the principle of conservation of energy, which states that energy cannot be created or destroyed, only transferred or converted from one form to another.

## 3. What is the second law of thermodynamics?

The second law of thermodynamics states that in any energy conversion, there will always be a decrease in the amount of useful energy and an increase in the amount of unusable energy, also known as entropy.

## 4. How is thermodynamics applied in real life?

Thermodynamics is applied in many areas of our daily lives, such as in the design of engines, refrigerators, air conditioners, and power plants. It is also crucial in understanding weather patterns and the functioning of the human body.

## 5. What is the difference between heat and temperature in thermodynamics?

Heat is the transfer of energy from a higher temperature object to a lower temperature object, while temperature is a measure of the average kinetic energy of the particles in a substance. In thermodynamics, heat is a form of energy, while temperature is a measure of the intensity of heat.

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