Physics Principles Flashcards
Atom
Unit of Matter
Protons, neutrons, electrons
Atomic Number
protons in nucleus of atom
Atomic Mass
proteins, neurons in nucleus
Isotope
Atom of element with unusual # of neutrons in nucleus
Strong, Interatomic Bonds
- Covalent Bonds: atoms share outer shell of electrons
- Ionic Bonds: transfer of electron btw atoms
Weak, Intermolecular Bonds
- Hydrogen bonds
- Van der Waals forces
–Dipole-dipole - btw polar substances
–London Dispersion forces - weakest, btw non polar substances
Fluid
Substance that deforms continuously under application of a shear (ie tangential) stress
Freezing Pt
Liquid –> solid
Boiling Pt
Liquid –> gas
Condensation Pt
Gas –> liquid
Melting Pt
Solid –> liquid
Latent Heat
Energy req’d to transform matter from one state to another
Critical Temperature
–gases can be liquified by increasing pressure or by cooling
–Temp at which no amt of pressure will liquify gas
Critical Pressure
Pressure above which liquid and gas cannot coexist at any temp
VP at critical temperature
Critical Volume
Volume occupied by one mole of gas at critical temp, pressure
Triple Point
T, P where all three states of substance coexist in thermodynamic equilibrium
Critical Point
Liquid, vapor
Gas, vapor forms of substance coexist with same density and are indistinguishable
R of triple pt
Newton’s First Law
Object remains at constant velocity unless acted on by an outside force
Newton’s Second Law
Force = Mass x Acceleration
Force: SI unit = Newton (kg*m/s^2)
Used for von Frey filaments, other aesthesiometers
von Frey Filaments
mechanical sensitivity test
thin plastic filaments applied to plantar surface of hind paw - filaments of different gauges/stiffness used to determine threshold that elects hind paw withdrawl
Velocity
Rate of change of position
Magnitude + direction
Vector
Acceleration
Rate of change of velocity
Newton’s third law
For every action, there is an equal and opposite reaction
Forces must add up
Weight
Measure of gravitational force exerted on mass
Weight = mass x acceleration DT gravity
Technically measured in Newton’s
M
Mass
Amt of matter an object contains
g
Energy
Capacity to Do Work
Work
Result of a force acting on an object in order to move said object
SI unit = joules (kg*m^2/s^2)
Work = force x distance (defibrillator)
Work = pressure x volume (PV loops)
Power
rate of doing work
SI unit = watt –> power expended when one Joule of work consumed in 1 second (J/s0
Efficiency
Efficiency = Energy output/energy input *100%
Pressure
Force per unit area
P=F/A
Pascal, Pa (N/m^2)
Newtonian Fluid
Viscosity unaffected by flow velocity, shear rate
Non Newtonian Fluid
Viscosity will change depending on shear rate