Last Minute Lecture

Equilibrium, Elasticity & Material Properties Explained | Chapter 11 of University Physics Chapter 11 examines how rigid bodies remain in balance under forces and how materials deform under stress. You’ll learn the conditions for static equilibrium, locate the center of gravity, construct free-body diagrams, and explore stress-strain behavior including Young’s, shear, and bulk moduli, as well as elastic versus plastic deformation. Conditions for Rigid-Body Equilibrium For a rigid body to be in equilibrium (static or dynamic), two requirements must hold: ΣF = 0 — No net external force (no translation) Στ = 0 — No net external torque about any axis (no rotation) These ensure the object remains at rest or moves with constant velocity without spinning. Center of Gravity & Stability The center of gravity is the point where an object’s weight can be assumed to act. Under uniform gravity, it coincides with the center of mass. Locating this point is crucial when ca...

Elasticity in Economics — Price Responsiveness, Demand, and Supply Explained | Chapter 5 of Principles of Microeconomics Why do some prices barely budge consumer habits, while others cause dramatic changes in what we buy or sell? Chapter 5 of Principles of Microeconomics tackles elasticity, one of the most important tools for analyzing how markets respond to changes in prices, income, and related goods. This summary will help you master the concept of elasticity and its real-world impact on buyers, sellers, and market outcomes. 🎥 Watch the full chapter summary below and subscribe to Last Minute Lecture for more textbook breakdowns and study tips! What Is Elasticity? Elasticity measures how much buyers and sellers respond to changes in market conditions. In economics, understanding elasticity reveals the degree to which quantity demanded or supplied reacts to price, income, or the prices of related goods. Price Elasticity of Demand The price elasticity ...