Physics: One-Dimensional Motion, Measurement, and Scientific Notation

Vocabulary flashcards covering one-dimensional kinematics, basic physics units and measurements, physical quantity classification, and significant figure rules.

Kinematics

A branch in physics that describes motion while ignoring the external agents that might have caused or modified the motion.

Translational Motion

Motion in which an entire object moves along a path, such as a car traveling on a highway.

Rotational Motion

Motion in which an object spins around an axis, such as Earth's spin on its axis.

Vibrational (or Periodic) Motion

Motion that repeats itself over equal periods of time, such as the back-and-forth movement of a pendulum.

Position

An object's location with respect to a chosen reference point.

Displacement

The change in position of an object, represented as $\Delta x = x_f - x_i$, where $x_f$ is the final position and $x_i$ is the initial position. It is a vector quantity and is independent of the path taken.

Distance

The length of the total path traveled by a particle; it is a scalar quantity.

Average Velocity

The rate at which displacement occurs, defined as $v_{x,\text{avg}} \triangleq \frac{\Delta x}{\Delta t} = \frac{x_f - x_i}{t_f - t_i}$. It is a vector quantity with SI units of $\text{m/s}$.

Average Speed

The rate at which the total distance occurs, defined as $v_{\text{avg}} = \frac{d}{t}$. It is a scalar quantity with no direction.

Instantaneous Velocity

The average velocity over an infinitesimally short time interval as the interval approaches zero, defined in calculus notation as $v_x \triangleq \lim_{\Delta t \rightarrow 0} \frac{\Delta x}{\Delta t} = \frac{dx}{dt}$.

Average Acceleration

The rate of change of velocity over a time interval, defined as \bar{a} = \frac{\Delta v}{\Delta t} = \frac{v_2 - v_1}{t_2 - t_1}, with SI units of $\text{m/s}^2$.

Instantaneous Acceleration

The limit of average acceleration as the time interval $\Delta t$ approaches zero, defined as $a_x = \frac{dv_x}{dt} = \frac{d^2 x}{dt^2}$.

Science

A system of knowledge and the methods used to find that knowledge.

Technology

The use of knowledge to solve practical problems.

Scientific Methods

A step-by-step process of investigation that follows: Problem (Question) -> Observe -> Hypothesize -> Experiment -> Conclusion -> Theory.

Six Major Areas of Physics

The main branches into which physics is divided: Classical Mechanics, Relativity (Modern Physics), Electromagnetism, Optics, Quantum Mechanics, and Nuclear Physics.

Physical Quantity

A measurable quantity specified by a numerical value and a unit of measurement (Physical Quantity = numerical value $\times$ unit of measurement). Classified into vector or scalar quantities.

Scalar Quantity

A physical quantity completely specified by a single value with an appropriate unit and no direction, such as volume, mass, speed, and time.

Vector Quantity

A physical quantity completely specified by a number, appropriate units, and a direction, such as displacement, velocity, acceleration, and force.

Fundamental Quantities

Basic quantities in physics—Length, Mass, and Time—from which all other physical quantities can be derived.

Derived Quantities

Quantities expressed as a mathematical combination of fundamental quantities, such as area, speed, and density.

Volume

The amount of space occupied by a body, with the SI unit of cubic meters ($\text{m}^3$).

Density

The ratio of mass per unit volume of a substance, with SI units of $\text{kg/m}^3$.

Scientific Notation

A expression of numerical magnitude written in standard form as $A \times 10^n$, where $1 \le A < 10$ and $n$ is an integer.

Significant Figures

All digits known with certainty in a measurement, plus one final digit that is estimated.

Sig Fig Multiplication and Division Rule

When multiplying or dividing several quantities, the number of significant figures in the final answer is limited to the smallest number of significant figures present in any term.

Sig Fig Addition and Subtraction Rule

When adding or subtracting numbers, the result should have a number of decimal places equal to the smallest number of decimal places in any term in the operation.