Questions and Answers
Which property characterizes the ability of solids to return to their original shape after the removal of an external force?
What is the correct definition of stress in the context of mechanical properties?
Which of the following correctly differentiates liquids from gases?
What is the SI unit for measuring stress?
Signup and view all the answers
Which characteristic of solids allows them to be drawn into thin wires?
Signup and view all the answers
What is the effect of applying an external force to a material regarding its strain?
Signup and view all the answers
What is the definition of Young's modulus?
Signup and view all the answers
Which of the following statements is true about fluids compared to solids?
Signup and view all the answers
Which of the following statements regarding tensile strain is accurate?
Signup and view all the answers
What distinguishes plasticity from elasticity in materials?
Signup and view all the answers
In the context of stresses, which type is related to the deformation due to internal forces acting parallel to the surface?
Signup and view all the answers
Which of the following best describes hydraulic stress?
Signup and view all the answers
What effect does a higher Young's modulus have on a material?
Signup and view all the answers
Which type of strain measures the change in volume relative to the original volume of a material?
Signup and view all the answers
What is the unit of Young's modulus?
Signup and view all the answers
Which modulus is defined as the ratio of shear stress to shear strain?
Signup and view all the answers
What best describes the relationship between stress and strain within the elastic limit?
Signup and view all the answers
Which type of modulus corresponds to the ratio of tensile stress to tensile strain?
Signup and view all the answers
What happens to a material when it exceeds its elastic limit?
Signup and view all the answers
In which type of stress does the force act perpendicular to the cross-section area?
Signup and view all the answers
Which formula represents the relationship between stress, strain, and modulus of elasticity?
Signup and view all the answers
Study Notes
Units and Measurements
- Physical quantity: A measurable property describing a system's state.
- Two types of quantities: Fundamental (basic physical attributes) and derived (combinations of fundamental quantities).
- Measurement includes two components: a number and a unit (e.g., 50 m, 5 s, 10 kg).
- Systems of units: CGS (centimeter, gram, second), FPS (foot, pound, second), MKS (meter, kilogram, second), and SI (International System of Units).
Phases of Matter
- Matter consists of atoms and molecules; light is not considered matter.
- Two main types of matter: Solids and Fluids.
- Solids: Rigid, with a definite shape and size, high density, and strong intermolecular forces, making them incompressible.
- Fluids:
- Liquids: Definite volume but no definite shape, low density, not easily compressible, and exhibit weak to moderate intermolecular forces.
- Gases: No definite shape or volume, very low density, easily compressible, and possess very weak intermolecular forces.
Mechanical Properties of Solids
- Elasticity: Ability to regain original shape upon removal of external force; does not change mechanical properties.
- Plasticity: Permanent deformation, where the material does not return to its original shape; often changes mechanical properties.
- Ductility: Capability of being drawn into thin wires or sheets; linked to malleability.
- Strength: Resistance to applied stress without failure.
- Stress: Internal restoring force per unit area due to applied external force, calculated as Stress = Force (F) / Area (A), measured in Pascal (Pa).
Strain
- Strain: Measure of deformation relative to an original length, indicating changes under stress.
- Strain formula: ΔL / Lo, where ΔL is change in length and Lo is original length.
- Strain is dimensionless—no units—and arises from stress.
Elasticity, Stress, and Strain
- Stress and strain exhibit proportionality until reaching the elastic limit, beyond which the material deforms permanently.
- Modulus of elasticity: Proportionality constant between stress and strain, defined as Stress = Modulus × Strain.
- Three types of modulus:
- Young’s modulus (longitudinal),
- Shear modulus,
- Bulk modulus.
Types of Stress and Strain
- Types of stress:
- Tensile stress: Stretching or compressive force along length.
- Shearing stress: Parallel force applied on a cross-section.
- Hydraulic stress: Force applied uniformly from all sides leading to volume changes.
- Types of strain:
- Tensile strain: (ΔL/L),
- Shear strain: (Δx/L),
- Volume strain: (ΔV/V).
Young’s Modulus (Y)
- Young’s modulus quantifies elasticity by relating longitudinal stress to longitudinal strain.
- Formula: Y = (F/A) / (ΔL/L) = FL / AΔL.
- Higher Young’s modulus indicates that more stress is needed for a small length change.
- SI Unit is Newton per square meter (N/m²) or Pascal (Pa).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers essential concepts of units and measurements in physical science. It includes fundamental and derived quantities, the role of measurement in describing physical properties, and different systems of units such as CGS, FPS, MKS, and SI. Test your knowledge on these foundational topics crucial for understanding the phases of matter.
