Summary of General Physics 1 (PHY 101) Content

Course Content Overview

The course covers foundational topics in General Physics, particularly focusing on mechanics, which includes concepts of space and time, units and dimensions, vectors and scalars, and Newton's laws of motion. Each topic is critical in understanding the principles governing physical phenomena.

Fundamental and Derived Units

• Fundamental Quantities: These include mass, length, time, temperature, electric current, and luminous intensity.
• Derived Quantities: These are defined based on fundamental quantities, such as area (length squared) and speed (length divided by time).
• Different systems of units like CGS (Centimeter-Gram-Second), FPS (Foot-Pound-Second), and MKS (Meter-Kilogram-Second) are used in measurements.

Dimensions and Dimensional Analysis

• Dimensions express the dependence of physical quantities on fundamental quantities of mass (M), length (L), and time (T).
• Dimensional Formula: Indicates how physical quantities relate to these fundamental dimensions. For example:
  • Force: [M^1L^1T^{-2}]
  • Speed: [M^0L^1T^{-1}]
• Principle of Homogeneity: The dimensions of the terms in a physical equation should be the same for the equation to be valid.

Motion and Newton's Laws

• Kinematics: Motion is described in terms of displacement, velocity, and acceleration.
• Newton's Laws of Motion:
  1. An object at rest remains at rest; an object in motion remains in motion unless acted upon by a net force (inertia).
  2. F = ma, where F is the net force, m is mass, and a is acceleration.
  3. For every action, there is an equal and opposite reaction (force pairs).

Conservation Principles

• Conservation of Energy: Total energy of an isolated system remains constant.
• Conservation of Momentum: If no external forces act on a system, its total momentum remains constant.

Gravitation and Orbital Mechanics

• Newton's Law of Gravitation: Every mass attracts another mass with a force proportional to the product of the two masses and inversely proportional to the squared distance between them. Formula: F = \frac{G m1 m2}{r^2}.
• Kepler's Laws describe planetary motion:
  1. Planets move in elliptical orbits with the Sun at one focus.
  2. A line connecting a planet to the Sun sweeps out equal areas in equal times.
  3. The square of the orbital period is proportional to the cube of the average distance from the Sun.

Rotational Dynamics

• Torque: A measure of the tendency of a force to rotate an object about an axis. Calculated as \tau = r \times F.
• Moment of Inertia: It quantifies how mass is distributed relative to an axis and influences rotational motion.

Summary of Learning Objectives

Students will develop an understanding of basic physical principles, the ability to perform dimensional analysis, the application of Newton's laws, and the ability to analyze motion in both linear and rotational contexts. They will learn to apply these principles to solve problems in classical mechanics and gravitational phenomena in their future studies in physics.