Learning Objectives
- Understand the concept of deformation and the properties of solids under stress and strain.
- Explain the relationships between stress, strain, and Young’s modulus.
- Analyze how materials behave under elastic and plastic deformation.
Language Objectives
- Use key terminology to describe deformation processes.
- Explain the behavior of solids using precise language and correct formulas.
- Collaborate effectively to discuss deformation scenarios in pairs or groups.
Terms (English and Kazakh)
| English Term | Kazakh Term |
|---|---|
| Stress | Қысым |
| Strain | Деформация |
| Elasticity | Серпімділік |
| Plasticity | Пластикалық |
| Young’s Modulus | Юнг модулі |
Glossary
- Stress: The *force* applied per unit *area* on an object.
- Strain: The measure of *deformation* an object experiences due to stress.
- Elasticity: The ability of a material to return to its original shape after being deformed.
- Plasticity: The ability of a material to permanently *deform* without breaking.
- Young’s Modulus: A measure of the stiffness of a material, calculated by the ratio of stress to strain.
Theory
When a force is applied to a solid material, it may experience *deformation*. The relationship between the applied *stress*</su_tooltip] and the resulting *strain*</su_tooltip] determines the material's behavior.
**Elastic Deformation** occurs when the material returns to its original shape after the stress is removed. The proportionality constant in this region is known as **Young’s Modulus**.
**Plastic Deformation** occurs when the material is permanently deformed and does not return to its original shape. This happens when the stress exceeds the material’s yield strength.
The formula for stress and strain is:
Stress = Force / Area
Strain = Change in Length / Original Length
Exercises on Terminology
Video Lesson
Examples and Solutions
Example: Calculate the stress on a material if a force of 200 N is applied over an area of 0.05 m².
Stress = Force / Area = 200 N / 0.05 m² = 4000 N/m²
To find the stress, we use the formula Stress = Force / Area. Here, the force is 200 N, and the area is 0.05 m². Substituting these values gives:
Stress = 200 / 0.05 = 4000 N/m².
Interactive Exercises
Research Task
Use this online simulator to explore stress and strain relationships:
Task: Vary the force and observe the deformation. Note how stress and strain change with the material’s properties.
- As force increases, stress and strain increase proportionally in the elastic region.
- Exceeding the yield strength leads to plastic deformation.
Group Activity
Work in pairs or groups to design an experiment that tests the deformation of different materials under varying stress. Record your results and compare the Young’s modulus of each material. Present your findings to the class or in an online discussion forum.
Reflection
Reflect on the lesson by answering the following questions:
- What is the difference between elastic and plastic deformation?
- How does Young’s modulus help us understand material properties?
- What real-world applications can you relate to these concepts?
Write your reflections in a journal or share them in a class forum.