Measurement and Motion Lecture Review

Flashcards covering measurement concepts, SI units, accuracy, precision, scalar and vector quantities, and types of motion based on the lecture transcripts.

Measurement

A process of determining or estimating the magnitude of a quantity involving comparison with a standard.

Direct Method

The process of taking measurement with the use of a measuring device, which produces Fundamental or Basic Physical Quantities.

Kelvin (K)

The SI unit for thermodynamic temperature, named after Lord Kelvin, where water freezes at $273\,K$, boils at $373\,K$, and absolute zero is $0\,K$.

Ampere (A)

The SI unit for electric current named after André-Marie Ampère; it is equal to the flow of approximately 6 quintillion ($6 \times 10^{18}$) electrons past a single point per second.

Ammeter

A basic measuring tool used to measure electric current.

Digital Balance

A basic measuring tool used to measure the amount of a substance.

Indirect Method

The process of taking measurement with the use of a formula or a combination of direct methods, leading to Derived Physical Quantities.

Hertz (Hz)

The unit used to measure frequency, such as those denoted by FM ($MHz$) and AM ($kHz$) radio stations.

Mass

The quantity of matter in a body; a scalar quantity that is constant everywhere in the universe, measured in kilograms ($kg$) with the formula $m = \frac{F}{a}$.

Weight

The gravitational force acted upon the mass of a body; a vector quantity that changes depending on location, measured in newtons ($N$) with the formula $W = mg$.

Mole (mol)

A shorthand way to talk about huge amounts of tiny things; one mole is equal to about 600 sextillion items, or 6 followed by 23 zeroes ($6 \times 10^{23}$).

Candela (cd)

The SI unit for Luminous Intensity, where one candela is approximately equal to the light given off by a single candle.

Meter (m)

Universal SI unit for length, defined as how far light travels in $\frac{1}{299,792,458}$ of a second through a vacuum.

Uncertainty

An aspect of measurement that indicates how much error is present and how much a number may differ from the actual 'true' value.

Significant Figures

Digits of value which carry meaning towards the resolution of the measurement, following specific rules for non-zero digits, zeros, and decimal placement.

Scientific Notation

A way for scientists to work with very large and very small numbers easily using powers of 10 (e.g., $4.5 \times 10^{4}$).

Accuracy

The closeness of a measurement to the true value of the quantity being measured, which can be determined with a single measurement and may be affected by systematic error.

Precision

A measure of the reproducibility of measurements, requiring several measurements to determine and potentially affected by random error.

Variance

The average of squared differences from the mean, used to measure how scattered data points are.

Standard Deviation

The square root of the variance, representing the average distance of each value from the mean.

Scalar Quantities

Mathematical quantities fully described by magnitude (numerical value) alone, such as distance, speed, time, energy, and mass.

Vector Quantities

Mathematical quantities fully described by both magnitude and direction, such as displacement, velocity, acceleration, force, and weight.

Head-Tail Method

A method of finding a resultant vector by placing the tail of the next vector at the head of the previous one and drawing a line from the first tail to the final head.

Parallelogram Method

A method of vector addition where vectors start at a common point and parallel lines are drawn to form a four-sided shape; the resultant is the diagonal.

Mechanics

The branch of physics that deals with the study of motion and the forces that affect objects.

Rectilinear Motion

The motion of bodies moving in a straight path.

Curvilinear Motion

The motion of bodies moving in a curved path.

Vibratory Motion

Repetitive back-and-forth motion around a central position, such as a swinging pendulum.

Translatory Motion

Motion in which all points of an object move in the same direction and at the same speed.

Acceleration

A vector quantity that occurs when an object speeds up or changes direction.

Uniform Motion

Motion in which an object moves at a steady or constant speed in a straight line without changing speed or direction.

Percentage Error

A calculation used to determine level of accuracy by finding the difference between experimental and true values, divided by the true value, and multiplied by $100\%$.