Thermal Physics 3.4

Question 1

define a thermodynamic system?

Answer 1

collection of molecules within a volume of space.

Question 2

define a isolated system ?

Answer 2

system which does not allow energy or matter to enter or leave.

Question 3

closed system?

Answer 3

matter cannot enter or leave

Question 4

heat engine?

Answer 4

system which converts thermal energy into mechanical work

Question 5

internal energy? (U)

Answer 5

sum of the potential and kinetic energies of its particles.

Question 6

why do particles have potential energy?

Answer 6

1. intermolecular bonds
2. chemical bonds
3. excited energy states in atoms
4. nuclear energy states.

Question 7

internal energy equation for a simple system:

Answer 7

U 3/2 p V

Question 8

internal equation for a monatomic gas:

Answer 8

U = 3/2 nRT

Question 9

define heat Q

Answer 9

spontaneous flow of energy in response to a difference i temperature. (high temp to low temp)

Question 10

thermal equilibrium?

Answer 10

2 systems in thermal contact

Question 11

equation for work providing pressure remains constant.

Answer 11

equation for work = pressure X change in volume.

Question 12

0th law of thermodynamics

Answer 12

1. if two systems are at the same temp - no flow of heat between them
2. if 2 objects are brought together at diff temperature then their is a flow of heat.

Question 13

define the first law of thermodynamics

Answer 13

when net heat flows into a system which does not work the internal energy changes according to the relationship. (FLT)

Question 14

first law of thermodynamics

Answer 14

change in internal energy(U) = heat input (Q) – work output (W)

Question 15

define the specific heat capacity?

Answer 15

= mass X SHC of a material X temperature change

Question 16

equation considering 2 equations in specific heat capacity.

Answer 16

heat loss by system 1 = heat gained by system 2

specific heat of capacity (system 1) = specific heat of capacity (system 2)

Question 17

equation of power for a engine

Answer 17

power max = no. of cylinders X engine frequency (work by expanding gasses - work done on mixtures)

Question 18

define a diabotic process

Answer 18

no heat transfer taken place in surroundings, its adiabatic cuz work takes time to transfer.

Question 19

define Isothermal process?

Answer 19

the gas does not change temperature.

Question 20

define Isobaric process

Answer 20

when pressure is constant.