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...

Newton’s Laws of Motion – Force, Mass & Acceleration Explained | Chapter 4 of University Physics Chapter 4 of University Physics introduces Newton’s three laws of motion, establishing the fundamental relationship between forces, mass, and acceleration. This chapter covers the definition of force, the distinction between contact and long-range forces, and how the net force governs the motion of objects. You’ll learn how to apply Newton’s first, second, and third laws and utilize free-body diagrams to analyze complex systems. Defining Force and Types of Forces A force is any push or pull that can cause an object to accelerate. Forces are vector quantities characterized by both magnitude and direction. They include contact forces (such as tension and friction) and long-range forces (such as gravity). To find the net force acting on an object, sum all individual forces vectorially using head-to-tail addition or component methods. Newton’s First Law: Inertia and Equilibriu...