Is the Change in Internal Energy Just 4513 J When No Work Is Done?

The system includes the pressure cooker, water, and steam. If 2.0 g of water is vaporized in a sealed pressure cooker with 4513 J of added heat, the change in the system's internal energy can be determined using the equation U = Q - W. Since the system is doing no work, the change in internal energy would be 4513 J. There is no other relevant information provided.
  • #1
yinnxz
3
0
Homework Statement
The lid of a pressure cooker forms a nearly
airtight seal. Steam builds up pressure and
increases temperature within the pressure
cooker so that food cooks faster than it does
in an ordinary pot. The system is defined as
the pressure cooker and the water and steam
within it.

If 2.0 g of water is sealed in a pressure
cooker and then vaporized by heating, and
4513 J must be added as heat to completely
vaporize the water, what is the change in the
system’s internal energy?
Relevant Equations
U = Q - W
Since the system is doing no work, would it be just 4513 J? I don't think there is any other information to use
 
Physics news on Phys.org
  • #2
yinnxz said:
Homework Statement: The lid of a pressure cooker forms a nearly
airtight seal. Steam builds up pressure and
increases temperature within the pressure
cooker so that food cooks faster than it does
in an ordinary pot. The system is defined as
the pressure cooker and the water and steam
within it.

If 2.0 g of water is sealed in a pressure
cooker and then vaporized by heating, and
4513 J must be added as heat to completely
vaporize the water, what is the change in the
system’s internal energy?
Relevant Equations: U = Q - W

Since the system is doing no work, would it be just 4513 J? I don't think there is any other information to use
Correct
 
  • Like
Likes yinnxz

1. What is the definition of "change in internal energy"?

The change in internal energy is a measure of the amount of energy that has been transferred into or out of a system. It can be caused by changes in temperature, pressure, or the addition or removal of matter.

2. How is the change in internal energy related to the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted from one form to another. The change in internal energy is a reflection of this principle, as it represents the amount of energy that has been transferred into or out of a system.

3. What factors can cause a change in internal energy?

Changes in temperature, pressure, or the addition or removal of matter can all cause a change in internal energy. Additionally, chemical reactions and phase changes can also result in a change in internal energy.

4. How is the change in internal energy calculated?

The change in internal energy is calculated by taking the difference between the final and initial internal energies of a system. It can be expressed as ΔU = Ufinal - Uinitial, where ΔU is the change in internal energy and U is the internal energy.

5. What are some real-world examples of a change in internal energy?

Examples of a change in internal energy include boiling water (a phase change), a battery powering a device (chemical reactions), and a car engine running (heat transfer from combustion). It can also be observed in everyday activities such as cooking, exercising, and using electronic devices.

Similar threads

  • Introductory Physics Homework Help
Replies
10
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
Replies
5
Views
328
  • Introductory Physics Homework Help
Replies
15
Views
361
  • Introductory Physics Homework Help
Replies
14
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
904
  • Introductory Physics Homework Help
2
Replies
58
Views
3K
  • Introductory Physics Homework Help
Replies
16
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
866
Back
Top