ENGR 100 Lecture Notes - Lecture 22: Kilogram
Document Summary
Newton"s second law (force = mass*acceleration) is invoked to derived force due to gravity. Mass is derived from newton"s second law. Distance, force, and time are fundamental dimensions measured in units od feet, pounds and seconds. Absolute system vs gravitational vs hybrid systems and if units are fundamental or derived. Standardized rules for correctly representing quantities with units should be followed. A physical quantity is written as a number or a formula representing a number, followed by unit symbols. The unit may be preceded by a magnitude prefix. The prefix is regarded as an inseparable part of the symbol. Magnitude prefixes in the si unit system by symbol, name and numerical value. Unit symbols are treated like algebraic factors that can be multiplied or divided with numbers or other unit symbols. Multiplication between units is indicated by a centered dot or a half-space. Division is indicated by a slash or a negative superscript.
