AP Physics 1 and 2 Notes

Flashcards for Thermodynamics, Electric Force, Magnetism, Circuits, Optics, and Waves

What is temperature a measure of?

Kinetic energy of particles

What unit is pressure measured in?

Pascals (Pa)

What are the characteristics of an Ideal Gas?

Molecules don’t attract or repel, move randomly at varying speeds, obey Newton’s Laws, and have perfectly elastic collisions.

What is heat?

Thermal energy transferred due to a temperature difference

What is the direction of Heat Flow?

From high temperature to low temperature

What happens to thermal energy once it is transferred?

Becomes internal energy

What are the three methods of heat transfer?

Conduction, Convection, and Radiation

What is the first law of thermodynamics?

Energy can’t be created or destroyed, only transferred

What is the second law of thermodynamics?

Entropy (disorder) in an isolated system only increases or stays the same at equilibrium

What are the four types of thermodynamic processes?

Isothermal, Isobaric, Isovolumetric/Isochoric, and Adiabatic

What is Coulomb's Law?

Two charges exert equal and opposite electric forces on each other

What is electric potential energy?

Stored energy due to the configuration of charged particles

How is charge acquired?

From the transfer of electrons from one atom to another

What are conductors able to do?

Allow the flow of electrons

What are insulators able to do?

Resist the flow of electrons

What are the three ways charges are accumulated?

Charging by friction, conduction, and induction

What is electric field?

A region in space influenced by an electric force

What is electric potential?

How a charge changes the space around it so that other charges placed there have energy

What is a capacitor?

A device that stores electric charge

What is capacitance?

A measure of how well a capacitor stores charge depending on its geometry

What does placing a dielectric between capacitor plates do?

Changes how the electric field behaves/moves

What is a circuit?

A complete path that electricity can flow through

What are the three components of a circuit?

Voltage source, conductor, and load

What is current?

The movement of charge when electrons begin to move

What is voltage?

The energy that pushes electric charges through a circuit; potential energy each charge has

What is resistance?

The opposition to the motion of charge

What is the total resistance of a circuit in SERIES?

The sum of the individual resistors

What is the total resistance of a circuit in PARALLEL?

The reciprocal sum of the individual resistances

What is power?

The rate at which electric energy is converted to heat or light

What are RC circuits?

Resistor + Capacitor circuit

What is time constant?

The time it takes for the capacitor to charge to approximately 63% of its maximum voltage or to discharge to about 37% of its initial voltage

What is Kirchhoff's Laws?

Laws that follow the conservation of charge and energy in electrical circuits

What is the Junction Rule?

The sum of current entering the intersection of wires is equal to the sum of current leaving the intersection of wires

What is the Closed Loop Rule?

The sum of the electric potential difference around any closed circuit is 0

What causes magnetism?

Magnetic dipoles created by rotational motion of electrons (spin)

What are ferromagnetic materials?

Atoms with all electrons spinning the same way and unpaired, making the atom magnetic

What is being measured when looking at domains, with magnetic orientations?

Orientation of groups of atoms

Is it possible to separate magnet poles?

No. There are no monopoles

Explain the Right Hand Rule

Index Finger: Points in the direction of the velocity of a particle. Middle Finger: Points in the direction of the magnetic field. Thumb: Points in the direction of force.

How do you predict force direction when the particle is an electron

Use the right hand rule, but the thumb (direction of the force) is in the opposite direction

What is a mass spectrometer?

A device which uses a magnetic field to measure the mass of particles

How are permanent magnets created?

Heating a ferromagnetic material, placing it in a strong magnetic field, and cooling quickly to lock the domains in place

How are temporary magnets created?

Bringing an object in contact with a strong magnetic field to align the domains

What is Paramagnetic behavior?

Can be temporarily magnetized (domains align) by an external field, but does not remain magnetic when it is removed

What is Diamagnetic behavior?

Dipoles weakly align oppositely to the external field, but the alignment stops when the external field is removed

Which version of the right hand rule can be used to determine the direction of the field produced by a wire carrying current?

Right hand rule version 2 where the thumb points in the direction of the current and your fingers will curl in the direction of the magnetic field

How do determine force acting on the current carring wire

By using the right hand rule

When can current be induced using a magnet?

By exposing the wire to a changing magnetic field

What is Faraday’s Law of Induction?

An emf is induced in an enclosed loop of wire when there is a rate of change of flux

What is Lenz’s Law?

An induced emf always allows a current whose magnetic field opposes the original change in flux

What is an electromagnetic wave?

A wave made of electric and magnetic fields that move through space together, carrying energy

How are electromagnetic waves transmitted?

By moving perpendicular to both the electric and magnetic fields

Which has radio waves or gamma rays have the longest wavelength?

Radio waves

Which is more energetic red or violet light?

Violet light

What is specular reflection?

When light bounces off a smooth, shiny surface in one direction

What is diffuse reflection?

When light hits a rough or uneven surface and scatters in many directions

What is Snell’s Law?

nsintheta = nsintheta

What happens when light enters a new medium?

Wave changes speed and wavelength, but frequency remains constant

What is dispersion?

When a prism separates white light into its constituent colors

What is total internal reflection?

When light traveling from a high index of refraction to a low index of refraction hits the boundary at a large enough angle and bounces back inside

What is the difference between convex and concave lenses?

Convex LENSES: Light rays CONVERGE to a focal point. Concave LENSES: Light rays DIVERGE away from each other.

What is unpolarized light?

Light that vibrates in many random directions perpendicular to its direction of travel

When does diffraction occur?

When light waves hit a barrier, the light bends from its straight-line path

What is interference?

The interaction of light rays after diffraction

What is a phase shift?

A change in phase by ½ wavelength that occurs when n2 > n1

What is a Concave MIRROR

A mirror whose reflecting surface is a segment of the inside of a sphere (Converging mirror)

What is a Convex MIRROR

A mirror whose reflecting surface is a segment of the outside of a sphere (Diverging mirror)

What are mechanical waves?

A disturbance which transfers energy and momentum through a medium with little or no net displacement of the particles in the medium

How do traveling waves form?

A source creates a disturbance, particles in the medium move, and the disturbance moves forward

What are the two types of mechanical waves?

Transverse and Longitudinal/Compression

What type of mechanical wave are density/pressure waves?

Longitudinal/Compression

What is a surface wave?

A wave that travels along the boundary between two different materials

Which state of matter do Waves travel FASTEST?

SOLIDS due to the tightly packed molecules

Which state of matter do Waves travel SLOWEST?

GASES due to widely spaced molecules

How does tension affect wave speed?

Higher tension —> Faster wave speed; Lower tension —> Slower wave speed

How does temperature affect wave speed for longitudinal waves in gases?

HIGH temperature —-> FASTER wave speed; LOW temperature —> SLOWER wave speed

What is frequency in terms of waves?

The vibration of a particle in a wave

Is frequency affected by the medium?

No. The frequency is determined by the source of the wave and is NOT AFFECTED by the medium

What happens when the amplitude (the maximum distance a wave movies away from its rest/equilibrium position) is changed

the pressure applies changes

What is sound?

Compression wave produced by vibrations causing the air to be compressed and rarefied

What happens to a wave at a fixed end boundary?

The wave is reflected back inverted

What is constructive interference?

Results in a larger amplitude

What is destructive interference?

Results in a smaller amplitude

What is the Doppler Effect?

The change in sound frequency due to the motion between the source of the sound and the observer

What is Beat Frequency?

When two sound waves constructively and destructively interfere

What are standing waves?

Caused by a disturbance/vibration of a medium

What are nodes?

Points of destructive interference with no motion

What are antinodes?

Points of constructive interference (amplitude)

What is Resonance?

Occurs when a forced vibration (disturbance) matches the resonant frequency of an object

What is fundamental frequency?

lowest frequency that produces a standing wave