Physics 1/2 (complete) Flashcards
what is a scalar
has only magnitude
what is a vector
has both magnitude and direction
what are some scalar quantities
length, area, volume
speed
mass, density
pressure
temperature
energy, entropy
work, power
what are some vector quantities
displacement
velocity
acceleration
momentum
force
lift, drag, thrust
weight
what is the definition of force
any force (visible/invisible) capable of causing a mass to accelerate
what is newtons first law of motion
lst = Interia
any object at rest will stay at rest, and an object in motion stays in motion, unless acted upon
inertia
capability of an object to resist changes in velocity
mass
measure of inertia
center of mass
weighted average of the mass of an object
what is newton’s second law
F=ma
a net force will increase velocity, but will maintain a constant acceleration
what is newton’s third law
when object 1 exerts a force on object 2, object 2 exerts an equal, but opposite force on object 1
what is velocity
speed
displacement over time
what does constant velocity mean?
- no acceleration (no net force, all forces sum to 0, object is in equilibrium)
- no change in direction
acceleration
change in velocity over time
what is the formula for distance traveled
d=1/2*at^2
d=distance
a=acceleration
t=time
what is the formula for velocity
v= square root of 2gh
v=velocity
g= acceleration due to gravity
h=distance
time in air
tair= 2v/g
when should air resistance be taken into consideration
only when the question says so
when is air resistance increased
when there is an increase in surface area, larger shape, and increased velocity
terminal velocity
point at which the forces due to gravity are matched by forces due to air resistance, resulting in no acceleration
gravity
any invisible field resulting in an attractive force between objects that have mass
constant field (near earth)
aka potential energy
PE=mgh
point charge (far from earth)
PE= - (GM1M2)/r
force due to gravity
F= (Gm1m2)/r^2
what is friction
nonconservative force occurring due to intermolecular interactions
prevents sliding
kinetic vs static friction
kinetic: object is accelerating
static: object is at rest
which coefficient is larger? static or kinetic
ALWAYS static
formula of density
d=m/V
general pressure equation
general pressure= force/area
pascal’s law
pressure applied in on part of an incompressible fluid is transmitted undiminished in all direction
bernoulli’s principle
pressure and velocity are inversely correlated
explain velocity and pressure in terms of window opening and air coming in
windows are down. at low velocities, there’s not much air entering the car, but at the high velocities air rushes in like crazy. as velocity increases, the pressure in your car decreases, and air flows from high pressure outside to low pressure inside
what is hooke’s law? what is another way to write it?
F=-kx
k= spring constant
x= distance spring is stretched
F=k*deltax
what is the specific gravity the ratio of
gravitational force and buoyant force
what is static object? (which forces are acting on the object)
no forces acting on the object, the object is at rest
what is the kinetic object? (what forces are acting on it)
no net force. object is moving, but not accelerating
what is torque
force applied at distance “I” from the point of rotation
what is energy
the capacity to do work
kinetic energy formula
1/2mv^2
what is the law of conservation of energy
energy in a closed, isolated system is always conserved
what is internal energy
energy dissipated as heat (SAME AS HEAT ENERGY)
what is heat energy
energy dissipated as heat (SAME AS INTERNAL ENERGY)
what is chemical energy
energy contained with chemical bonds
energy stored/released by the separation of electrons
what is mechanical energy
sum of kinetic and potential energy in a system
what are the 4 ways to think of work
- work = change in energy
- work = force applied over a distance
- 1st law of thermodynamics: change in the energy of a system is due to either work or energy
- work-energy theory: if work is done on an object, the work done is equal to the change in kinetic energy of the object
what is the purpose of a simple machine
to reduce the force needed to perform a given amount of work, but it DOES NOT decrease the amount of work needed
when thinking of power, what is the 4 ways to think about it?
- P= change of energy/time
- P=work/time
- P= (force times dcostheta)/time
4.Pinstantaneous = force x velocity x costheta
when it comes to negative and positive change, how does it connect to the amount of electrons
negative: excess of electrons
positive: shortage of electrons
conductance promotes movement of? what do insulators inhibit?
the movement of electrons, insulators inhibit the movement of electrons
what is the electric field
invisible influence capable of exerting a force on a mass or charge
what is voltage
electrical potential energy caused by the separation of charge
potential energy per unit charge
what is a current? what is the charge?
current is the flow of POSITIVE charge
flows in opposite direction of electron flow
change in charge over time
what is the equation of resistance
R= (pL)/A
p=resistivity
L=length
A= cross-sectional area
what is Ohm’s law
V=IR
R= constant (resistance)
V= voltage
I= current
magnetism is similar to what
electricity
what are magnetic fields created by
changing electric fields
what is the curl right hand rule
direction of magnetic field (the way the fingers fold in when you do thumbs up)
direction of current flow (the way the thumb goes - up)
what is fleming’s right hand rule
thumb: direction of force
first finger: direction of field
middle finger: direction of current
(hand is held up with thumb facing up, first finger facing out, and middle finger facing inward at 90 degrees)
what are circuits? does it flow the same with electron flow?
think of current as the flow of positive change
- flows in the opposite direction of electron flow
what does the switch open __/ ___ and
close ____ mean
open: circuit is open and incomplete
closed: circuit is closed and complete
what is the equation for capacitors in parallel?
Ctotal = C1+C2+C3
think of a box with the capacitors in a straight vertical line
capacitors are the open ones
what is the equation for capacitors in series
1/Ctotal = 1/C1 + 1/C2 + 1/C3
thing of a box with the open capacitors in a horizontal straight line
capacitors are the open ones
what is the equation for resistors in series
Rtotal= R1+R2+R3
think of a box with resistors in straight horizontal line
resistors are the ones with squiggly lines
what is the equation for resistors in parallel?
1/Rtotal = 1/R1 + 1/R2 + 1/R3
think of a box with the resistors in a straight vertical line
resistors are the ones with squiggly lines
how to batteries in series differ from batteries in parallel?
think in terms of voltage, current and capacity
series: add voltage together, current and capacity stay the same
parallel: add current or capacity together, voltage stays the same
what is the equation of electrical power
power= current x voltage
P=IV
for sound/mechanical waves, how does intensity relate to amplitude and frequency
intensity is proportional to amplitude and frequency
for light waves, how does intensity relate to amplitude and frequency
intensity is ONLY proportional to amplitude
electromagnetic waves are
transverse waves capable of propagating without a medium, transfer energy and momentum
mechanical waves
require a medium to propagate, only transfer energy (not matter)
what is the wave speed equation
v=λf
v=speed/velocity
λ= wavelength
f= frequency
transverse waves
strings on a musical instrument
longitudinal waves
sound waves
3 wave rules
what is wave speed determined by?
does frequency change from medium to medium? how about wavelength
wave speed is determined by the medium
frequency NEVER changes from medium to medium
wavelength DOES change from medium to medium
what is a node on standing waves? how about antinodes
node: middle intersection from the wave
antinode: the not intersecting part
what is the doppler effect
the greater the relative velocity, the greater the shift in frequency or wavelength
higher pitch means (higher/lower) frequency
higher pitch = higher frequency
do vibrations travel through solids?
liquids?
gas?
solids and liquids - yes
they create pressure waves through gases
how is sound created
by a vibrating medium
light can exist as what two things?
particle and wave
what is the equation for energy of a photon
E=hf
h=planck’s constant
f= frequency
what ‘nm’ is visible light
390-700
when looking at a wave, how do you see energy and wavelength
the tighter the waves, the decrease wavelength and increasing energy
the more spread out the waves, the increasing of the wavelength and the decreasing of energy
on the spectrum, how do rays/waves fit
gamma, xray, visible light, radio waves, IR, UV
least to largest
gamma
xray
UV
visible
IR
radio
what is snell’s law
n= c/v
n= index of refraction of a medium
c= speed of light in vacuum
v= speed of light in the medium
virtual images are (upright/inverted) and (negative/positive)
virtual images are upright and negative
real images are (upright/inverted) and (negative/positive)
real images are inverted and positive
what is a converging lens and what is it used for
it is the fat lens
usually a positive, real, inverted image
what is a diverging lens and what is it used for
skinny lens
always negative, virtual, upright image
where is the image focused in nearsightedness
visual image is focused in front of retina
where is the image focused in farsightedness
visual image is focused behind the retina
normal vision interacts how with retina
normal vision occurs when light is focused directed on the retina rather than in front or behind
two lens system
the image of the first lens becomes the object for the second lens
photoelectric effect
When light shines on a metal, electrons can be ejected from the surface of the metal (bounces)
young’s double slit
light is passed through two slits and forms an interference pattern on a screen behind the slits
what are the 2 formulas for frequency/wavelength?
from those 2 formulas, how can you get the formula for energy?
photon energy: E= hf (f=frequency, and h=constant: 6.626x10^-34)
frequency: f=c/l (c=light constant: 3x10^8), and l=length
this would mean: E= hc/l
potential energy formula
PE=mgh
what is the Venturi/Bernoulli’s effect
speed of a liquid increases, the pressure drops
Buoyant force - definition and formula
upward force a fluid exerts on an object
F=pvg
p= density
v=volume
g=gravitational constant
what is the gravitational constant
9.8 m/s^2
when given an open container with liquid and closed container with liquid, which would have the higher pressure and why?
the open container
the open one would have absolute pressure (SUM OF GAUGE PRESSURE AND ABSOLUTE PRESSURE) while the closed container would only have gauge pressure
difference in the equation for frictional force vs normal force
frictional uses SIN (mgsin theta)
normal uses COS (mg cos theta)
