Physics: Vibrational Motion, Waves, and Electricity

Comprehensive flashcards covering the principles of vibrational motion, wave behavior, sound, and fundamental electric circuit laws based on the lecture notes.

Vibrational Motion

Movement back and forth around a stable equilibrium position (rest position).

Periodic Motion

A special type of motion that repeats itself at regular time intervals.

Simple Harmonic Motion (SHM)

A vibrational motion where the restoring force is directly proportional to the displacement of the body and is always directed toward the equilibrium point (opposite to displacement), assuming friction is neglected.

Restoring Force ($F_{rest}$)

The force exerted by a spring on a mass to return it to the equilibrium position.

Amplitude ($A$)

The maximum displacement of a body from its rest (equilibrium) position, often represented as half the distance between the two furthest points reached.

Frequency ($f$)

The number of complete vibrations occurring in one second, measured in Hertz ($Hz$) or ($s^{-1}$).

Periodic Time ($T$)

The time required to complete one full cycle or vibration, measured in seconds ($s$).

Angular Velocity ($\omega$)

The magnitude of angular displacement swept by the radius per unit of time, measured in units of ($rad/s$).

Simple Pendulum Periodic Time

Calculated by the formula T = 2\text{\pi} \sqrt{\frac{L}{g}}, where $L$ is the length of the string and $g$ is the acceleration due to gravity.

Mechanical Waves

Waves that require a material medium to travel through, such as sound waves and water waves.

Electromagnetic Waves

Waves that do not require a material medium to travel through, such as light and radio waves.

Transverse Waves

Waves in which the motion of the particles of the medium is perpendicular to the direction of wave propagation, forming crests and troughs.

Longitudinal Waves

Waves in which the particles of the medium move in the same direction as the wave propagation, consisting of compressions and rarefactions, such as sound waves.

Reflection of Sound

The rebounding of sound waves when they encounter a reflecting surface.

Refraction of Sound

The change in direction of sound waves when they transition between two media of different densities, such as air and oxygen.

Superposition Principle

The principle stating that when two waves meet, the resulting total displacement is the sum of the individual displacements of the waves.

Interference

The result of the overlap of a group of waves of the same type and frequency; it can be constructive (waves support each other) or destructive (waves cancel each other).

Diffraction of Sound

The bending of waves around obstacles or as they pass through limited openings relative to their wavelength.

Standing Waves (Stationary Waves)

Waves resulting from the superposition of two identical sets of waves traveling in opposite directions with the same frequency and amplitude.

Nodes

Points in a standing wave where the amplitude is zero.

Antinodes

Points in a standing wave where the amplitude is at its maximum.

Neutral Atom

An atom that contains an equal number of electrons and protons, making its net charge zero.

Charging by Friction

The transfer of electrons from one body to another by rubbing them together, such as rubbing wool and plastic.

Law of Conservation of Charge

States that electric charge is neither created nor destroyed, only transferred from one material to another.

Coulomb

The International System unit of charge, equivalent to the charge of approximately $6.24 \times 10^{18}$ electrons.

Coulomb's Law

States that the electrical force between two charged bodies is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them: $F = k\frac{q_1q_2}{d^2}$.

Coulomb Constant ($k$)

The value in air or vacuum equals approximately $9 \times 10^9\,Nm^2/C^2$.

Electric Current ($I$)

The flow of electric charges, measured in Amperes ($A$), where $1\,A = 1\,C/s$.

Potential Difference ($V$)

The amount of work (energy) done to move a unit of charge between two points, measured in Volts ($V$).

Electromotive Force (EMF)

The potential energy per unit charge (one Coulomb) required to move electrons between two points in a circuit.

Electric Resistance ($R$)

The opposition faced by electrons as they travel through a conductor due to collisions, measured in Ohms ($\Omega$).

Ohm's Law

States that the potential difference across a constant resistance is directly proportional to the current flowing through it, expressed as $R = \frac{V}{I}$.

Resistivity ($\rho$)

A property that depends on the type of material and temperature, measured in ($\Omega\cdot m$).

Superconductors

Materials whose electrical resistance becomes zero at very low temperatures.

Electric Power ($P$)

The rate at which electrical energy is converted to other forms (mechanical, thermal, etc.), measured in Watts ($W$).

Kilowatt-hour ($kWh$)

A unit of energy commonly used by electricity companies, where conversion to Joules requires multiplying by $3.6 \times 10^6$.

Series Circuit

A circuit current path where current is the same in all parts ($I_{eq} = I_1 = I_2$) and total resistance is the sum of individual resistances ($R_{eq} = R_1 + R_2 + R_3$).

Parallel Circuit

A circuit with multiple paths where potential difference ($V$) is the same across all branches, and the reciprocal of equivalent resistance is the sum of the reciprocals of branch resistances.