physics Flashcards
SI units include …
- meter
- kilogram
- second
- ampere
- mole
- kelvin
- candela
physical quantities with BOTH magnitude and direction
what are vectors?
vector qualities include …
- displacement
- velocity
- acceleration
- force
quantities with magnitude, but NO direction
what are scalars?
scalar quantities include …
- speed
- coefficient of friction
use pythagorean theorem to break vector into components
vector addition
change the direction of the subtracted vector, then use pythagorean theorem
vector subtraction
multiplying vector by scalar changes _
magnitude
result of multiplying two vectors using dot products
scalar quantity
result of multiplying two vectors using cross product
vector quality
product of vectors’ magnitudes and cosine of angle
what is dot product?
product og vectors’ magnitudes and sine of angle
what is cross product?
vector representation of a change in position
what is displacement?
displacement is _ of path
independent
_ equals straight line distance between start and end positions
displacement
scalar quantity reflecting oath traveled
what is distance?
(vector) change in displacement with respect to time
what is velocity?
total displacement divided by total time
what is average velocity?
total distance divided by total time
what is average speed?
limit of the change in displacement over time (as time approaches 0)
what is instantaneous velocity?
magnitude of instantaneous velocity vector
what is instantaneous speed?
any push or pull; has potential to result in acceleration
what is force?
attractive force that opposes motion as a function of electrostatic interactions at surface between two objects
what is friction?
force that exists between two objects that are not in motion relative to each other
what is static friction?
force that exists between two objects in motion relative to each other
what is kinetic friction?
kinetic friction is a _ value whereas static friction depends on magnitude of applied force
constant
_ depends on two materials in contact
coefficient of friction
coefficient of static friction is always _ than coefficient of kinetic friction
higher
measure of the inertia on an object; amount of material
what is mass?
force experienced by given mass du to gravitational attraction to Earth
what is weight?
(vector) change in velocity over time
what is acceleration?
an object will remain at rest or move with constant velocity if there is no net force on object
what is newton’s first law of motion?
any acceleration is the result of the sum of forces acting on an object and its mass
what is newton’s second law of motion?
any two objects interacting with one another experience equal and opposite forces as a result
what is newton’s third law of motion?
velocity and acceleration vectors are parallel or antiparallel
what is linear motion?
free fall is a type of _ motion
linear
contains x and y component; only acted upon by gravity (if air resistance is negligible)
what is projectile motion?
(2D movement) dimensions are parallel and perpendicular to surface of the plane
what are inclined planes?
motion with radial and tangential dimensions
what is circular motion?
centripetal force points _
radially inwards
the only force in uniform circular motion is _
centripetal force
instantaneous velocity always points _
tangentially
representations of forces acting on an object
what are free body diagrams?
occurs in absence of net forces acting on object
what is translational equilibrium?
an object in translational equilibrium has constant _
velocity
occurs in absence of net torques acting on object
rotational equilibrium
an object in rotational equilibrium has constant _
angular velocity
property of a system that enables it to do or make something happen
what is energy?
the SI unit for all forms of energy
whar are joules (J)?
energy associated with movement of objects
what is kinetic energy?
kinetic energy depends on …
mass, speed (squared)
energy stored within a system
what is potential energy?
_ energy has four forms:
1. gravitational
2. electric
3. elastic
4. chemical
potential
relates to mass of an object and its height above datum
what is gravitational energy?
zero-point
what is datum?
related to spring constant and degree of stretch-compression of a spring squared
what is electronic potential energy?
measure of the stiffness of a spring
what is the spring constant?
the potential energy between charged particles
what is electrical energy?
energy stored in bonds of compounds
what is chemical energy?
sum of kinetic and potential energies of a system
what is total mechanical energy?
(path independent) forces that do not dissipate mechanical energy of a system
what are conservative forces?
if there are only conservative forces acting on an object, total mechanical energy is _
conserved
(path dependent) forces that cause dissipation of mechanical energy from a system
what are nonconservative forces?
while total energy is conserved, some mechanical energy is _ (thermal or chemical energy)
lost
process by which energy is transferred from one system to another
what is work?
work may be expressed as the area under _
pressure-volume curve
rate at which work is done or energy is transferred
what is power?
the SI unit for power
what are watts (W)?
when net work is done on/by a system, its kinetic energy will change by the same amount
what is the work-energy theorem?
the factor by which a simple machine multiplies the input force to accomplish work
what is mechanical advantage?
simple machines provide the benefit of _
mechanical advantage
mechanical advantage makes it easier to accomplish work becaise input force needed is _
reduced
output force of a simple machine
what is load?
input force of a simple machine
what is effort?
ratio of machine’s work output to input when nonconservative forces are taken into account
what is efficiency?
