Class Three

Question 1

closed system

Answer 1

environment cannot contribute matter to it

Question 2

isolated system

Answer 2

environment cannot contribute energy or matter

Question 3

open system

Answer 3

environment is free to interact with the system

Question 4

how can the total energy in a system change

Answer 4

if energy is transferred into or out of a system

Question 5

temperature vs thermal energy

Answer 5

temperature = intensive

thermal energy = extensive

Question 6

what is heat (q)

Answer 6

transfer of thermal energy between a system and its environment

Question 7

what does the zeroth law of thermodynamics state

Answer 7

objects A and B = thermal equilibrium

objects B and C = thermal equilibrium

then A and C must be in equilibrium as well

Question 8

kinetic energy and temperature equation

Answer 8

Question 9

what is k_b and when is it used

Answer 9

1.38 x 10^-23 J/K

used when looking at the relationship with kinetic energy and temperature

Question 10

three ways heat transfer occurs

Answer 10

conduction

convection

radiation

Question 11

what conducts heat well

Answer 11

metals

Question 12

what is convection

Answer 12

heat expanding + becoming less dense than surrounding air → heat rise

Question 13

what is radiation

Answer 13

heat transfer by absorption of energy carried by light waves

Question 14

as the temperature of materials increase..

Answer 14

they expand

Question 15

first law of thermodynamics

Answer 15

total energy of the universe is constant → energy cannot be created or destroyed

Question 16

equation for first law of thermodynamics

Answer 16

difference in E = Q - W

Question 17

when is work (W) considered positive

Answer 17

when work is being done by the system on the environment

Question 18

what is an isobaric process

Answer 18

one that occurs at constant pressure

Question 19

what is an isochoric process

Answer 19

one that maintains a constant volume

Question 20

is work done in isochoric processes

Answer 20

no

Question 21

when does an isothermal process occur

Answer 21

when heat is allowed to pass freely between a system and its environment

Question 22

in an isobaric process..

Answer 22

W = P (change in V)

Question 23

in an isochoric process..

Answer 23

W = 0

change in E = Q

Question 24

in an isothermal process..

Answer 24

change in E = 0

Q = W

Question 25

what happens in an adiabatic process

Answer 25

no heat is transferred between the system and the environment (all energy is transferred as work)

Question 26

second law of thermodynamics

Answer 26

entry of an isolated system either stays the same or increases during thermodynamic processes

Question 27

first law equation for isobaric processes

Answer 27

delta E = Q - (P)(delta V)

Question 28

which process has delta E = 0

Answer 28

isochoric processes

Question 29

first law equation for isothermal processes

Answer 29

Q = W

Question 30

first law for adiabatic processes

Answer 30

delta E = - W

Question 31

isothermal vs adiabatic

Answer 31

isothermal = temp is constant but heat moves in/out adiabatic = no heat moves in/out but temp changes

Question 32

what is density

Answer 32

mass / volume

Question 33

density of water

Answer 33

1 g / cm³

Question 34

what is specific gravity

Answer 34

how dense something is compared to water density of substance / density of water

Question 35

for which phase does the density change with pressure/temperature

Answer 35

gas, not liquids or gases

Question 36

density of an ideal gas

Answer 36

mP / nRT

Question 37

F_grav formula for fluids questions

Answer 37

F_grav = pVg density x volume x gravity

Question 38

pressure for fluids formula

Answer 38

P = force / area

Question 39

hydrostatic gauge pressure formula

Answer 39

P_gauge = p_fluidgD g = gravity D = depth of sheet

Question 40

incompressible liquids

Answer 40

density is constant (doesn't increase with depth)

Question 41

what is buoyancy

Answer 41

net upward fluid force

Question 42

Archimedes' Principle

Answer 42

the magnitude of the buoyant force is equal to the weight of the fluid displaced by the object

Question 43

Archimedes' Principle formula

Answer 43

F_Buoy = p_fluidV_subg

Question 44

floating object in equilibrium on surface equation

Answer 44

w_object = F_Buoy V_sub / V = p_object / p_fluid

Question 45

what does it mean if p_object \> p_fluid

Answer 45

then the object will float and fraction of its volume thats submerged = ratio of its density to fluid's density

Question 46

Pascal's law

Answer 46

pressure applied to an enclosed fluid will be transmitted without a change in magnitude to every point of the fluid and to the walls of the container

Question 47

slow rate equation

Answer 47

f = Av

Question 48

surface tension ____ as temperature increases

Answer 48

decreases

Question 49

continuity equation (flow rate)

Answer 49

A₁v₁ = A₂v₂

Question 50

if a tube narrows.. the flow speed \_\_\_

Answer 50

increases

Question 51

4 requirements for an ideal fluid

Answer 51

fluid is incompressible there is negligible viscosity flow is laminar flow rate is steady

Question 52

the Bernoulli effect

Answer 52

pressure is lower where flow speed is greater

Question 53

3 ways forces can be applied to an object

Answer 53

tension (stretching) compression (squeezing) shear (bending)

Question 54

stress formula

Answer 54

force / area

Question 55

tensile/compressive strain formula

Answer 55

change in length / original length

Question 56

shear strain formula

Answer 56

distance of shear / original length

Question 57

Hooke's law

Answer 57

stress and strain are proportional

Question 58

Young's modulus

Answer 58

constant of proportionality for tensile/compressive stress

Question 59

shear modulus

Answer 59

constant of proportionality for shear stress

Question 60

the stronger the intermolecular bonds, the ____ the modulus

Answer 60

greater

Question 61

tension/compression formila

Answer 61

delta L = F (original length) / EA

Question 62

shear formula

Answer 62

X = F (original length) / AG

Question 63

faster flow speed = ____ pressure

Answer 63

lower

Question 64

resistivity is ____ proportional to temperature

Answer 64

linearly