Last Minute Lecture

Electric Charge & Electric Fields Explained | Chapter 21 of University Physics Chapter 21 lays the groundwork for understanding electrostatics by exploring how objects acquire charge, how charged particles interact via Coulomb’s law, and how the electric field concept unifies these interactions. This chapter also shows how to visualize fields with field lines and calculate fields for both point charges and continuous charge distributions. Watch the full video summary on YouTube for step-by-step examples and field visualizations. Electric Charge & Conservation Electric charge comes in two types—positive and negative—with like charges repelling and opposites attracting. Protons carry positive charge, electrons negative, and neutrons are neutral. The conservation of charge principle states that the total charge in a closed system remains constant, meaning charge can be transferred but never created or destroyed. Charging by Friction, Polarization & Induction Obj...

Mechanical Waves – Propagation, Energy & Superposition Explained | Chapter 15 of University Physics Chapter 15 explores how mechanical waves transport energy through media without bulk matter motion. From transverse and longitudinal disturbances to standing wave patterns, this chapter provides the tools to model, analyze, and apply wave behavior across strings, air, and fluids. Watch the full video summary here for detailed derivations and real-world examples. Types of Mechanical Waves Transverse waves – Particle motion ⟂ wave direction (e.g., waves on strings). Longitudinal waves – Particle motion ∥ wave direction (e.g., sound in air). Surface waves – Combine transverse and longitudinal motion (e.g., water waves). Wave Parameters & Periodic Waves Key parameters describe any periodic wave: Amplitude (A): Maximum displacement from equilibrium. Wavelength (λ): Distance between repeating points. Frequency (f): Cycles per second, f = 1/T. P...