Final Exam 2026 Physics Vocabulary Review: Momentum through Current Electricity

Momentum and Impulse

Momentum: Defined as inertia in motion. It is a property of matter that is consistently conserved during a collision.
Symbol for Momentum: Represented by a lowercase $p$ .
Equation for Momentum: $p = m \times v$ .
Unit for Momentum: Expressed as $kg \cdot m/s$ .
Requirements for Changing Momentum: An external force is required, which is defined as a force originating from outside the system being studied.
Newton's Second Law (Original Form): Newton originally described the second law of motion in terms of the change in momentum using the equation $F = \frac{\Delta p}{t}$ .
Impulse-Momentum Theorem: The equation describing the change in momentum: $F \times t = \Delta m \times v$ or $F \times t = m_f v_f - m_i v_i$ .
Impulse Symbol: Represented as $F\Delta t$ .
Impulse: Defined as the force acting on an object multiplied by the time duration during which that force acts. Practically, impulse represents how much an external force changes the momentum of an object.
Unit for Impulse: Measured in $N \cdot s$ (Newton-seconds) or $kg \cdot m/s$ .

Conservation of Momentum and Systems

Conserved: A term meaning a quantity remains unchanged throughout a process; it must be identical before and after an event.
System: Refers to the collection of all objects whose motion is currently being analyzed or interested in.
External Forces: Forces exerted on an object from outside the established frame of reference. These are the cause of changes in momentum.
Internal Forces: Forces exerted on an object from within the established frame of reference. These do not cause a net change in the momentum of the system.
Law of Conservation of Momentum: States that if no external forces act upon a system of objects, the total momentum of that system remains unchanged.
Closed System: A system that does not lose or gain mass.
Isolated System: A specific type of closed system where there is no net external force acting upon it.

Types of Collisions

Momentum Conservation in Collisions: Momentum is always conserved when a collision happens.
Elastic Collision: A collision where both energy and momentum are conserved. Typically, these occur when field forces collide, such as magnetic bumpers on carts.
Inelastic Collision: A collision where momentum is conserved, but mechanical energy is not conserved. The representative equation is $m_1 v_{1i} + m_2 v_{2i} = m_1 v_{1f} + m_2 v_{2f}$ .
Perfectly Inelastic Collision: A collision where objects stick together after impact and share the same final velocity ( $v_f$ ). While momentum is conserved, mechanical energy is not.
Explosive Collision: A scenario where one object breaks into multiple pieces. In this type of collision, momentum is conserved, but mechanical energy is not conserved; rather, mechanical energy is gained.

Electrostatics and Charge

Electrostatics: The scientific study of electric charges that can be collected and held in a single place.
Neutral: The state when positive charges exactly balance the negative charges in an object.
Insulator: A material through which an electric charge will not move easily.
Conductor: A material, such as copper, through which an electric charge will move easily.
Electroscope: A specialized device used to detect electric charges. It consists of a metal knob connected by a metal stem to two thin metal leaves.
Charging by Contact (Conduction): The process of charging a neutral body by allowing it to touch a charged body.
Charging by Induction: The process of charging an object without any physical contact.
Polarization: A temporary separation of charges in a nonconductor caused by the proximity of a nearby charge.
Grounding: The process of removing excess charge from an object by touching it to the Earth.
Coulomb's Law: States that the force between two charges varies directly with the product of their charges and inversely with the square of the distance between them. This equation allows for the prediction of electrostatic force between two charged particles.
Coulomb ( $C$ ): The SI standard unit of charge. One coulomb is the magnitude of the charge of $6.24 \times 10^{18}$ electrons or protons.
Elementary Charge: The magnitude of the charge of a single electron or a single proton.

Electric Fields and Potential

Electric Field: The field existing around any charged object. It produces forces capable of doing work and transferring energy from the field to another charged object. Charged objects interact with this field.
Electric Field Line: Visual representations providing a picture of an electric field. Spacing between lines indicates field strength. They never cross and are directed toward negative charges and away from positive charges.
Volt ( $V$ ): The unit of electric potential difference, equal to one joule per coulomb ( $1\,J/C$ ).
Electric Potential Difference: The change in potential energy per unit charge within an electric field, expressed in Volts.
Reference Level: The specific position where the potential energy is determined to be exactly zero.
Electric Motor: An apparatus that specifically converts electric energy into rotational kinetic energy.

Energy, Work, and Power

Energy: A property of an object describing its ability to produce a change in itself or the world around it. It is always conserved though it may change forms.
Mechanical Energy: The energy an object possesses due to its motion or its position. With no outside forces present, mechanical energy will remain constant.
Kinetic Energy ( $KE$ ): Energy resulting specifically from motion. Equation: $KE = \frac{1}{2} m v^2$ .
Elastic Potential Energy: The energy stored within a pulled string.
Thermal Energy: The internal energy in substances results from the vibration and movement of atoms.
Conservation of Energy: A fundamental law stating energy can never be created or destroyed. It is constant in the universe and can only change forms.
Joule ( $J$ ): The standard unit of energy.
Work ( $W$ ): A measure of how much a force changes the energy of a system. It is calculated as the product of the force and the displacement in the direction of the force causing that displacement.
Work-Energy Theorem: States that work is equal to the change in kinetic energy of an object when the only change to the object is its speed.
Power ( $P$ ): The rate at which work is performed. Equation: $P = \frac{W}{t}$ .
Watt ( $W$ ): Defined as one joule of energy transferred in one second ( $1\,J/s$ ). This is the unit for power.

Simple Harmonic Motion and Waves

Periodic Motion: Any motion that repeats itself in a regular, predictable cycle.
Simple Harmonic Motion (SHM): Motion that occurs when the restoring force on an object is directly proportional to the object's displacement from its equilibrium position.
Period ( $T$ ): In periodic motion, the amount of time required for an object to repeat one complete cycle of motion.
Amplitude: In periodic motion, the maximum distance an object moves from its equilibrium position.
Hooke's Law: States that the forces acting on a spring are directly proportional to the amount the spring is stretched.
Resonance: A special form of SHM that occurs when small forces are applied at regular intervals to an oscillating or vibrating object, causing the amplitude of the vibration to increase.
Pendulum: Consists of a massive object called a bob suspended by a string or light rod. When disturbed from equilibrium, it moves in simple harmonic motion for small angles.
Restoring Force: The force that attempts to return an object back to its equilibrium position.
Wave: A disturbance that carries energy through matter or space. It transfers energy without transferring matter.
Wave Pulse: A single disturbance or pulse traveling through a medium.
Periodic Wave: A mechanical wave that moves up and down at a consistent, same rate.
Mechanical Wave: A disturbance that moves through a physical medium.
Traveling Wave: A wave where the wave crest moves through a medium from one location to another.
Transverse Wave: A mechanical wave that vibrates perpendicular to the direction of the wave's motion.
Longitudinal Wave: A mechanical wave in which the disturbance is in the same direction as (parallel to) the direction of the wave motion.
Crest: The high point of a wave.
Trough: The low point of a wave.
Wavelength ( $\lambda$ ): The shortest distance between points where the wave pattern repeats, such as from crest to crest or trough to trough.
Frequency ( $f$ ): The number of complete oscillations a wave makes in one second, measured in Hertz ( $Hz$ ).

Wave Interactions and Superposition

Principle of Superposition: States that the displacement of a medium caused by two or more waves is the algebraic sum of the displacements of the individual waves.
Interference: Results from the superposition of two or more waves.
- Constructive Interference: The resultant wave has a larger amplitude.
- Destructive Interference: The resultant wave has a smaller amplitude.
Node: The stationary point where two equal wave pulses meet in the same location, resulting in a displacement of zero.
Antinode: The point of largest displacement when two wave pulses meet.
Standing Wave: A wave that appears to be standing still, produced by the interference of two traveling waves moving in opposite directions.
Reflection: Occurs when a wave strikes a boundary it cannot pass through or be absorbed by. The ray will change directions according to the Law of Reflection.
Reflected Wave: The specific wave that bounces back from a boundary.

Electric Current and Circuits

Electric Current ( $I$ ): The flow of electrical charges or charged particles.
Conventional Current: A flow of positive charges moving from high potential to low potential.
Ampere ( $A$ ): The unit of electric current, equal to a flow of one coulomb per second ( $1\,C/s$ ).
Battery: A device composed of several galvanic cells connected together that converts chemical energy into electrical energy.
Electric Circuit: A closed loop or pathway that allows electrical charges to flow.
Resistance ( $R$ ): A property that determines how much current will flow; it is equal to voltage divided by current.
Resistor: A device with a specific resistance. It may be constructed of long thin wires, graphite, or semiconductors. Often used to control current in circuits.
Voltage ( $V$ ): Refers to the electrical potential difference.
Direct Current (DC): When charge only flows in one direction within a circuit.
Series Circuit: A type of connection in which there is only a single path for the current.
Parallel Circuit: A type of connection featuring two or more paths from one place on a circuit to another. The potential difference across the voltmeter equals the potential difference across the circuit element.
Combination Series-Parallel Circuit: An electric circuit that includes both series and parallel branches.
Equivalent Resistance: The sum of all resistances in a circuit. Calculation must account for whether resistors are in series or parallel.
Short Circuit: Occurs when a very low resistance circuit is formed, causing a very large current which can potentially start a fire.
Ammeter: A low-resistance device connected in series used to measure electric current in any branch of a circuit.
Voltmeter: A high-resistance device used to measure the voltage drop across any portion or combination of portions of a circuit; it is connected in parallel with the part being measured.

Acoustics and Sound

Sound Wave: A pressure vibration transmitted through matter as a longitudinal wave.
Pitch: A person's interpretation of frequency. It depends on the frequency of a sound wave and is categorized as "high" or "low."
Loudness: A factor perceived by the ear that depends primarily on the amplitude of the wave the observer hears.
Sound Intensity: The amplitude of a sound wave. Symbol: $I$ . Units: $W/m^2$ .
Sound Intensity Level: A logarithmic scale measuring the amplitudes of sound humans can hear. Symbol: $\beta$ .
Decibel ( $dB$ ): The unit for sound intensity level. It indicates that sound amplitude is being compared to another sound using a log scale.
Compressions: The region of a medium where particles are compressed together by vibrations.
Rarefactions: The region of a medium where particles are spread apart by vibrations.
Doppler Effect: The change in frequency caused by a moving source, a moving detector, or both.
Fundamental: The lowest resonant frequency, which is the lowest frequency where standing waves occur.
Harmonics: Multiples of the fundamental frequency.