FINAL: highlighted material Flashcards
something that can be perceived through the senses, or a fact or occurrence thereof
phenomenon
a fixed and reproducible amount for taking accurate measurements
unit
the forward flow of events
time (a fundamental quantity)
a set of standard units
system
the 3D space an object occupies
volume
what are the 5 senses used to gather information?
- sight (most used by humans)
- hearing
- taste
- smell
- touch
most scientific knowledge stops at what level?
the theory level
what are 2 features that make time unique?
- time does not go backwards, only forwards
- something must happen for time to exist
what are the other names for the metric system?
- S.I. (International System)
- M.K.S. System (Meter, Kilogram, Second)
what are the two parts of standard scientific notation?
- a number between 1 and 10 (the coefficient)
- a power of 10
large numbers have positive or negative powers of ten in scientific notation?
positive powers of ten
what are the units for mass, and the units for volume?
- mass: grams (and cg, mg, kg…)
- volume: m^3, km^3…
- also, L, mL, KL
location based on a reference point is…
position
the fastest an object can fall in air is called ___
terminal velocity
something that is shot or thrown is called ____
a projectile
what quantity needs size, units, and direction?
a vector
a world clue in a problem that indicates the initial velocity = 0 is…
when a problem says that the object is waiting for the light to turn green.
both equations for vertical motion assume what?
no air resistance
the quantity capable of changing an object’s motion
force
the law stating that for every action, there is an equal and opposite reaction
Newton’s Third Law of Motion
a change in momentum is referred to as…
impulse
what did the ancient Greeks believe w/r/t motion?
that objects tended toward rest.
force is a ___ quantity
vector
what’s really happening with centrifugal force?
the object’s inertia is trying to keep it in a straight path
the ability to do work is defined as….
energy
energy of motion
kinetic energy
kinetic energy + potential energy is called…
total energy
work is what type of quantity?
scalar
do work and energy have the same units?
yes, Joule (J)
work can be thought of as…
a transfer of energy
why do we eat food?
for the potential energy it contains
examples of renewable energy sources?
- wind
- solar
- geothermal
what is the initial source of energy for most life on earth?
the sun
the relative measure of the kinetic energy of an object’s particles
temperature
name for a food calorie, which is 1000x bigger than a regular, “little c” calorie
“big C” calorie
ice below 0 degrees Celsius
subcooled ice
the process of going directly from a solid to a gas
sublimation
heat transfer by energy only
radiation
which temperature scale is an absolute one, which starts at zero?
Kelvin
how are boiling and evaporation different?
evaporation is slow and natural compared to boiling
even though pure water is said to boil at 100 degrees Celsius, where is that only technically true?
at sea level, where the full atmosphere can hold the water molecules down. water at any level higher than sea level will have an actual boiling point of less than 100 degress Celsius
what is a feature of water that is unusual?
water is less dense in its solid phase than its liquid phase - e.g., ice floats.
at what point is water at its most dense?
about 4 degrees Celsius.
how does dew form?
the air holds a certain amount of moisture based on its temperature. as the air cools overnight, it can’t hold all of its moisture, so the extra moisture comes out on cooler surfaces (like grass, or a car) as “dew”
what is an example of a heat engine?
a car engine.
what is an example of plasma?
the sun.
the propogation of energy through a medium is called a…
wave
the time required to complete one cycle
period
longitudinal waves through matter are what we refer to as….
sound
the perceived “highness” of a sound
pitch
the logarithmic scale of sound intensity
decibel
areas of minimum movement in a standing wave
nodes
the lowest frequency of a note played on a musical instrument
fundamental frequency
examples of electromagnetic waves?
- radiowaves
- microwaves
- infared
- ultraviolet
- x-rays
- gamma rays
“deep blue” visible light
wavelength = 390 nm
F = 7.7 x 10^14 Hz
the range of human hearing
20 Hz to 20 kHz
examples of a low pitched sound?
- rolling thunder
- foghorn
how does the doppler effect occur?
as the source comes toward the observer the wave gets “bunched” up to a higher frequency. when the source is going away from the observer the wave gets spread out.
how are two instruments playing the same note alike?
both have the same fundamental frequency
the change in direction when a wave strikes a surface or boundary
reflection
when different wavelengths spread out
dispersion
how waves interact
interference
light with a specific orientation
polarized light
nearsightedness
myopia
how are waves of light throught to travel?
in a straight line from their source, until they contact a surface or boundary
what are two examples of total internal reflection?
- fiberoptic cables
- water fountains lit from the bottom
why do diamonds show flashes of color, and what word is associated with this?
good total internal reflection causes the light to come out the top. referred to as “fire”
what’s an example of diffraction grating?
the color spokes from a CD (compact disc)
can our eyes tell the difference between polarized and unpolarized light?
no
examples of a convex mirror?
- the outside part of a spoon
- security mirrors
when an object is any distance from a convex mirror, the image will be…
upright, reduced, and virtual
what causes and fixes hyperopia?
- the lens can’t work with the eyeball and focuses light too far back
- a converging lens corrects this
the flow of electrons is called ____
electricity
opposition to electric flow is called ____
resistance
a current where electrons only flow one way
direct current (DC)
examples: anything that runs off a battery - phone, car, etc
a circuit with a break in the path
open circuit
voltage can hurt you, but ___ can kill you
current
how do “new style” Xmas lights work?
each bulb has a shunt resistor that acts as a bypass if the filament breaks.
what type of plug grounds best, and how does it work?
3-prong plug w/ a dedicated ground - the dedicated ground is different (cylindrical) from the other prongs, and is a better method as electricity only flows through when needed. used in larger appliances (fridge, A/C unit)
how does an iron nail act like a magnet?
each little spot on the surface of the nail (called a domain) has its own random magnetic orientation. a permanent magnet forces the domains to line up. this is called domain alignment. when the nail is removed from the permanent magnet, the domain becomes random again.
where is the magnetic south pole located?
near, but not at, the geographic north pole.
how does a transformer work?
electrons flow into the primary side and create a magnetic field around the primary loops. the electrons then reverse course, and the magnetic field collapses and regrows in the opposite orientation. the secondary loops sense this changing magnetic field, and by electromagnetic induction, a secondary current is created that shadows the primary side.
why doesn’t DC electricity work in a transformer?
the electrons don’t chance directions in DC (direct current - electrons only flow in one direction), so the magnetic field never changes.
