Semester 2 Final Study Guide

Flashcards for Semester 2 Final Study Guide

Charge

The property assigned to electric charges, measured in Coulombs (C).

Current

Flow of charge, usually due to a difference in voltage.

Resistance

The amount that a material 'dislikes' allowing charge to flow.

Electric Potential

The amount of electric potential energy per charge (V = EPE / Q), also known as voltage.

Ohm’s Law

V = IR, the relationship between electric potential, resistance, and current flow.

Coulomb’s Law

F = (kq1q2) / d^2, the relationship between charge, distance, and force between charged particles.

AC Current

Electric current that changes flow direction at a certain frequency (e.g., 60 Hz in the US).

DC Current

Electric current that flows only in one direction.

Speed of Electricity

Electricity propagates at nearly the speed of light, but electrons move much slower (1 mm/s or less).

What is necessary for a circuit to run?

A voltage source and a complete circuit connecting two conductive input/output points.

What is an electric field?

A force field representing the electric force on a positive charge, goes from positive to negative providing information about direction and magnitude of electric force in an area.

Electric Fields

A force field created by charged particles or objects, pointing from positive to negative.

Magnetic Fields

A force field created by a magnet or moving charge, pointing from North to South. Applies force on other magnets or moving charges.

Frequency & Period

Frequency (f) is how many times something happens in a second (Hz), period (T) is how long something takes to happen once (seconds).

Wavelength

The length of a single cycle of a wave, usually in meters.

Amplitude

A measurement representing the amount of vibration in a wave.

Wave Speed

The speed a wave is traveling, usually in m/s.

Longitudinal vs. Transverse Waves

Longitudinal waves have vibrations parallel to the wave direction (e.g., sound), transverse waves have vibrations perpendicular (e.g., light).

Doppler Effect

Apparent change in wave frequency due to relative motion between source and observer.

Standing Wave

Two waves of same wavelength, frequency, and amplitude traveling in opposite directions interfere, creating a wave that appears to move up and down in place.

Interference

Waves traveling through the same medium combine amplitudes, leading to increases or decreases.

Reflection

When a wave bounces off a boundary between two mediums.

Refraction

When a wave passes through a boundary and changes direction due to angle of incidence and change in speed/wavelength.

Sound

A longitudinal wave that is energy traveling as a vibration in a physical medium.

Sonic Boom

A cone of constructive interference following an object moving faster than sound.

What is a wave?

Energy traveling as a vibration that moves as time passes, caused by a vibration.

What is an echo?

Sound reflecting off a boundary.

Does frequency and wavelength affect sound?

Determines pitch and energy, assuming constant wave speed.

What is the speed of sound?

~340 m/s at room temperature, varies with temperature and air composition.

What is the frequency of a beat created by a 200 Hz and 203 Hz sound?

The difference between the two frequencies.

Temperature

A measurement to track how hot or cold things are, representing translational kinetic energy in molecules.

Heat

The energy that transfers from higher to lower temperature substances when in contact.

Fahrenheit/Celsius/Kelvin

Three unit measurements of temperature, know how to convert between them.

Specific Heat Capacity

Represents how much heat is transformed into temperature when absorbed by a material.

Thermal Radiation

Electromagnetic waves emitted by any object based on temperature.

Condensation

Gas turning into liquid on cooler objects, heating the object with the energy from phase change.

Evaporation

Liquid evaporating into gas, using thermal energy from the substance, and cooling the remaining liquid.

Entropy

Disorder, chaos, or messiness, always increasing in nature, takes work to reduce.

Adiabatic Process

A process in which a substance (usually a gas) is expanded and compressed to do mechanical work instead of creating heat.

Carnot Efficiency

A measurement of the maximum efficiency of a heat engine.

How does the high specific heat capacity of water effect the Earth’s climate?

Area's near water tend to have milder climates that don’t have drastic temperature swings because the water in the area absorbs so much energy. Also, areas that are near warm ocean currents tend to stay warmer, and areas near cold ocean currents tend to be cooler.

Electromagnetic Waves

Traveling vibration in electromagnetic fields, not through a physical medium.

Light Refraction

When light passes through a boundary and changes direction.

Electromagnetic Spectrum

Range of EM wave frequencies, including radio, microwaves, infrared, light, UV, X-rays, gamma rays.

Color

Our name for different frequencies of the visible light spectrum.

Lens

A shaped transparent material designed to bend light in a specific way.

Real Image

Image created when light rays intersect, can be projected.

Virtual Image

Image seen by looking into mirror/lens, can’t be projected.

What is an electromagnetic wave?

A traveling vibration in electromagnetic fields, caused by a moving or vibrating charge.

What is light?

Transverse electromagnetic wave our eyes detect.

What is color?

Different materials absorbing/reflecting/transmitting different frequencies of light.

What is the law of reflection?

The angle of incidence of a ray = the angle of reflection

How does the temperature of an object affect thermal radiation?

Warmer objects emit more thermal radiation at shorter wavelengths.

What is heat transfer?

The process of thermal energy transfer from a hotter object to a cooler object.

Conduction

Heat transfer through direct contact.

Convection

Heat transfer through the movement of fluids (liquids or gases).

Radiation

Heat transfer through electromagnetic waves.

Is Entropy always increasing in a closed system?

Yes, without external work, entropy tends to increase, leading to more disorder.

What is diffraction?

The bending of waves around obstacles or through openings.

What is superposition?

When two or more waves overlap in the same space, their amplitudes add together.

What is polarization?

The alignment of the electric field vector of light waves in a specific direction.

What is the relationship between frequency, wavelength, and wave speed?

Wave speed = Frequency x Wavelength (v = f \lambda)

What is index of refraction?

A measure of how much light slows down when passing through a medium.

What is Snell's Law?

The relationship between the angles of incidence and refraction and the indices of refraction of the two media. (n1\sin(\theta1) = n2\sin(\theta2)).