Physics Chapter 1 - Units and Measurement

Flashcards for Physics Chapter 1 focusing on Units and Measurement, designed to help students review lecture notes and prepare for exams.

Unit (in Measurement)

Comparison with a certain basic, arbitrarily chosen, internationally accepted reference standard.

Result of Measurement

A number accompanied by a unit.

Fundamental Units

Units for the fundamental or base quantities.

Derived Units

Units obtained for the derived quantities, expressed as combinations of base units.

System of Units

Complete set of units, includes both base and derived units.

CGS System Base Units

Centimetre, gram, and second.

FPS (British) System Base Units

Foot, pound, and second.

MKS System Base Units

Metre, kilogram, and second.

Système Internationale d’ Unites (SI)

Internationally accepted system of units for measurement.

Plane Angle (dθ)

Ratio of length of arc to the radius.

Unit for Plane Angle

Radian (rad)

Solid Angle (dΩ)

Ratio of intercepted area to the square of radius.

Unit for Solid Angle

Steradian (sr)

Significant Digits (Figures)

Includes all digits known reliably plus the first digit that is uncertain.

Order of Magnitude

The power of 10 in scientific notation, providing an approximate idea of the number's size.

Significant Figures Rule (Multiplication/Division)

In multiplication or division, the final result retains as many significant figures as in the original number with the least significant figures.

Significant Figures Rule (Addition/Subtraction)

Final result retains as many decimal places as are there in the number with the least decimal places.

Rounding Off

A method to simplify numbers in computation that contain more than one uncertain digit.

Dimensional Formula

Shows how and which base quantities represent the dimensions of a physical quantity.

Dimensional Equation

Equating a physical quantity with its dimensional formula.

Principle of Homogeneity of Dimensions

Only physical quantities with the same dimensions can be added or subtracted.

Dimensions of Speed

The dimensions on both sides of the equation, when simplified, must be of length/time, or [L T–1]