Units of Measurements | GEN PHYSICS 1 | TagLish Video Lesson

The video introduces the concept of measurement in General Physics 1, defining physical quantities as any measurable physical property. These quantities are expressed as a combination of a numerical value and a unit. It also distinguishes between two main unit systems: the SI (metric) system, commonly used in the Philippines, and the English (imperial) system, used in the United States.

The discussion moves to fundamental and derived units. Fundamental units are based on physical quantities that are primary and independent, such as length, mass, and time. Derived units, on the other hand, are mathematically combined from fundamental units, for example, speed (length/time). The video lists the seven SI base units: meter (length), kilogram (mass), second (time), ampere (electric current), Kelvin (temperature), mole (amount of substance), and candela (luminous intensity), along with their symbols.

The video then explains metric prefixes, which are added to the beginning of units to denote multiples or submultiples of the base unit. Examples include 'Peta' (10^15), 'Tera' (10^12), 'Giga' (10^9), 'Mega' (10^6), 'Kilo' (10^3), 'Hecto' (10^2), 'Deca' (10^1) for larger values, and 'Deci' (10^-1), 'Centi' (10^-2), 'Milli' (10^-3), 'Micro' (10^-6), 'Nano' (10^-9), 'Pico' (10^-12), and 'Femto' (10^-15) for smaller values. These prefixes help in expressing very large or very small measurements conveniently.

Unit conversion is introduced as a process using a 'conversion factor' – a ratio expressing how many of one unit are equal to another. The video provides several examples of converting between units, such as millimeters to meters, liters to milliliters, kilograms to grams, seconds to minutes, and meters to centimeters. The answers to these conversion problems are then revealed to demonstrate the application of conversion factors.

The video explains scientific notation as a method for writing extremely large or small numbers concisely, which would otherwise be difficult to express as decimals. It demonstrates how to convert numbers into scientific notation, emphasizing that the coefficient must be between 1 and 10 (inclusive of 1, exclusive of 10). The exponent's sign (positive or negative) depends on the direction the decimal point is moved: moving left results in a positive exponent, and moving right results in a negative exponent.

Several examples are provided to practice converting numbers into scientific notation. These examples cover both very small numbers (starting with zero point something) and large whole numbers. The video clarifies the rules for determining the exponent based on decimal point movement and reinforces the importance of the coefficient's range. It concludes by summarizing the topics covered: unit conversion and scientific notation.