Physics Semester 2 Vocabulary
-commonly used unit for heat, defined as the amount of heat required to raise the temperature of 1 gram of water by 1 degree Celcius, unit of energy
-1000 calories (heat used to raise temp of 1 kilogram of water by 1 degree Celcius, unit of energy
-An apparatus for measuring the amount of heat involved in a chemical reaction or other process.
-quantity that tells how hot or cold something is compared with a standard, expressed by a number that corresponds to a degree mark on some chosen scale
-measure of average kinetic energy of all particles in sample (not speed)
-indication of avg translational energy not total
-temp scale (most commonly used) where 0 is temp where water freezes and 100 is where water boils, gap dividing into degrees
-temp scale used in US, 32 is temp where water freezes, 212 is where water boils
-temp scale used in scientific research SI scale, based on celcius scale, but 0 is the absolute zero temp, corresponds to -273 on celcius scale
-the energy that transfers from one object to another because of temp diff between them is called heat (heat goes from hot to cold)
-Q stands for geat
-when heat flows from 1 object or substance to another it is in contact with the objects/substances are in thermal contact, heat flows from high temp to low temp
-objects in thermal contact reach same temp and no more heat is flowing between them
-grand total of all energies inside a substance
-the energy of a substance due to random motion of its component particles, is equal to total energy of those particles
-U is internal energy, measured in Joules
how is internal energy related to temperature
-generally increasing U involves PE due to relative positions as well as KE
zeroth law of thermodynamics
-two systems individually in thermal equilibrium with a 3rd system are and must be in thermal equilibrium with each other
-two diff metal fused together with diff coefficients of thermal expansion so when heated expand at different rates bend and curve and when cooled contract at diff rates
specific heat capacity
-quantity of heat required to raise temp of unit mass of substance by 1 degree celcius, often called specific heat or heat capacity
-water has a high specific heat capacity
-practical application of bimetallic strip, back and forth bending of bimetallic coil opens and closes an electric circuit, when room is too cold coil bends towards brass side closing electrical switch to turn on heat and when room is too hot coil bends towards iron side opening the switch and turning of heating
-heat transferred within or between diff materials in direct contact
-materials that conduct well
-ex metals, copper, silver, aluminum
-poo heat conductors like wood wool straw paper cork and styrofoam which delay the transfer of heat
-concrete, plastic, home insulator, wood, cork
-heat transfer through fluid
-heat transfer through no medium: ex sun warming earth or heat from heat radiator
-any energy including heat that's transmitted bu radiation, a form of electromagnetic waves, includes radio waves, x rays, and gamma rays
-study of heat and its transformation into mechanical energy
-limit of heat lowest heat where no more energy can be extracted from a substance and temp can't go any lower
first law of thermodynamics
-when heat is added to a system, it transforms to an equal amount of some other form of energy
-heat added= increase in internal energy + external work done by the system
-delta U= Q-W
2nd law of thermodynamics
-heat will never of itself flow from a cold object to a hot object
conservation of energy
-thermal energy is conserved
-delta PE + delta KE + delta U = 0
-flow of heat energy of a hot body to a cooler body without transfer of matter
-altering material or mixture from 1 phase to another
-energy absorbed or released during a change of sate at a constant temp and pressure
heat of fusion
-energy required to convert solid to liquid with no temp
heat of vaporization
-energy required to convert liquid to gas with no temp change
electricity at rest (involves electric charges, the forces between them, and their behavior in materials)
aura that surrounds electric charges
usually in equilibrium on you
+attracts- and vica versa
nucleas-+, electrons surround--,all es are identical, usally have = es and ps so zero net charge
ps and ns
as many ps as es
net + charge
net – charge
atoms and matter
Conservation of charge
cannot be destroyed or created
charge between 2 diff objects with know distance
SI unit of charge
materials in which outer es are not anchored to the nucleas, are “loose”
electrons are tightly bound
materials sometimes behave like conductors sometimes like insulators, material that can be made to behave as either a conductor or an insulator of electricity
material that has infinite conductivity at very low temps so that charge flows through it without resistance
3 ways of charging
-charging by contact without rubbing -charging through induction (attracting or repelling but not touching) -charging by friction
letting charge move onto a conductor by touching it
(all ps on one side ex on the other)
a little more negative on one side than the other, electric dipole moment is a measure of the separation of positive and negative electrical charges in a system of charges, that is, a measure of the charge system's overall polarity (Electrical polarity (positive and negative))
electrons flow from
positive to negative
heat flows from
hot to cold
magnetic dipoles flow from
north to south
why do transverse and longitudinal waves need a medium to travel through?
-are compression waves, need matter to compress, transverse depends on density of medium and longitudinal too
-change in frequency of a wave dye to motion of source or receiver
-moving closer is higher frequency and moving away is lower frequency
doppler effect equation
index of refraction
-the ratio of the velocity of light in a vacuum to that in a medium.
law od reflection
-angle of incidence for a wave taht striles a surface is = to angle of reglection
-the ejection of electrons from cetain metal when expose to cetain frequencies of light, prove hat lgiht is photons and waves
-Wave–particle duality postulates that all particles exhibit both wave and particle properties.
-measure of amount of disorder in a system
irreversibility of heat energy transformations
-In thermodynamics, a change in the thermodynamic state of a system and all of its surroundings cannot be precisely restored to its initial state by infinitesimal changes in some property of the system without expenditure of energy.
determining half life
-time required for ald the atoms of a radioative isotope of an element to decay.
how forces on electrons make a motor work
-The forces on the moving electrons in the current of wires in the electric motor are perpendicular to the direction of motion of the electron current. That force makes the armature (The rotating coil or coils of a dynamo or electric motor.) move.
-phenomonem of inducing a voltage in s conductor by changing the magnetic field near the conductor
-charging of object without direct contact
properties of a magnet
-1. Magnets attract objects of iron, cobalt and nickel.
2. The force of attraction of a magnet is greater at its poles than in the middle.
3. Like poles of two magnets repel each other.
4. Opposite poles of two magnets attracts each other.
5. If a bar magnet is suspended by a thread and if it is free to rotate, its South Pole will move towards the North Pole of the earth and vice versa.
relationship between strength of magnet and # of times wire wrapped around it
-A simple electromagnet consisting of a coil of insulated wire wrapped around an iron core. The strength of magnetic field generated is proportional to the amount of current.
law of superposition
-he principle of superposition may be applied to waves whenever two (or more) waves travelling through the same medium at the same time. The waves pass through each other without being disturbed. The net displacement of the medium at any point in space or time, is simply the sum of the individual wave displacements.
-writtena s cirla with a
series circuit calculation
-v sum of
parallel circuit calculation
-i sum of
-A bell-shaped glass cover used for covering delicate objects or used in a laboratory, typically for enclosing samples.
-massless energy, neutral charge
-emits two protons and two electrons positive charge)
atomic mass number
-total # of nucleons\number of protons
-negative charge, steam of electrons
gamma ray emission
-during gamma radioacive decat emit electromagnetic waves
-measure of radioactive decay, half like is time needed for half of radioactive atoms to decay
-Positron emission or beta plus decay (β+ decay) is a particular type of radioactive decay and a subtype of beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (νe). Positron emission is mediated by the weak force. T
-e spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation.
-when nucleus emits alpha or beta paricle, diff element firomed, changing of one element to another called transmutation
-material that is radioactive.
-Snell's law (also known as the Snell–Descartes law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, hen referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass and air.
-radio, microwave, infared, ultrabiolet, x ray, gamma ways
visibile light spectrum
-Roy G. Biv
-first long wavelength low frequencieas then short wavelengths high frequencies
device used to store charge in a circuit
speed of light
speed of sound
specific heat capacity of
minimum angle of incidence for which a light ray is totally reflected within a medium