Properties of Matter
Elasticity, fluid pressure, and structural properties.
Matter exhibits unique properties when subjected to forces. Solids stretch and compress elastically, while fluids transmit pressure and exert buoyant forces.
This unit covers solid elasticity (Hooke's Law, Young's Modulus), hydrostatic fluid pressure, and Archimedes' Principle of buoyancy.
Key Takeaways
- •Hooke's Law states that spring extension is directly proportional to the applied stretching force.
- •Young's Modulus measures the stiffness of solid materials, representing stress divided by strain.
- •Archimedes' Principle states that buoyant force equals the weight of the fluid displaced by the object.
Core Concepts & Definitions
1Elasticity & Hooke's Law
Elasticity is the property of a body to regain its original shape after deforming forces are removed.
•Hooke's Law: F = -k * x, where k is the spring constant.
•Elastic limit is the threshold beyond which permanent deformation occurs.
2Archimedes' Buoyancy Principle
Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced.
•F_buoy = ρ_fluid * V_submerged * g.
•An object floats if its density is less than the fluid's density.
Quick Revision Notes
- •Stress is force per unit area (N/m² or Pascals). Strain is fractional deformation (dimensionless).
- •The area under the linear elastic region of a stress-strain curve represents elastic energy storage density.