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Flashcards in Physics Deck (150)
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1

what is temperature the measure of ?

average KE of particles in a substance

2

0 kelvin is how many degrees Celsius ?

-273

3

what is heat measured as ?

Joules

4

what is heat a sum of ?

kinetic energy of all particles

5

what does increasing distance between particles do to the bonds?

decreases the strength

6

why does the temp of a substance not increase during melting/boiling ?

additional energy used to break intermolecular bonds

7

what is latent heat ?

the amount of energy needed to change the state of a substance

8

name the 4 factors of condensation

temp / surface temp / airflow / density

9

why is rate of condensation higher with greater density ?

particles closer - stronger forces

10

what is evaporation ?

liquid changing to a gas without boiling (average KE of particles is below BP)

11

individual particles only evaporate if ...

- high KE
- travelling towards surface

12

name the 4 factors of evaporation

temp / airflow / density / surface area

13

define conduction

process of vibrating particles passing on their KE to neighbouring particles in a material

14

why are metals good conductors ?

ions are tightly bound
free electrons can transfer energy

15

why are non-metals not very good at conducting ?

no free electrons

16

what is a fluid ?

substance with no fixed shape

17

what is convection ?

transport of heat energy through a fluid

18

why does hot air rise ?

less dense due to particles moving further apart from each other

19

what is the term for the cycle of hot air rising and cold air replacing it ?

convection currents

20

what is radiation (heat) ?

heat transfer from the emission of electromagnetic waves from warm bodies

21

why can radiation travel through space ?

does not require a medium

22

what is power the rate of ?

rate of energy change

23

power =

energy / time

24

what are the best absorbers and emitters of radiation ?

dark matte objects

25

what are the worst absorbers and emitters of radiation ?

bright and glossy objects

26

give the factors of heat transfer

SA / vol / material

27

list the features of a vacuum flask

- vacuum between container and flask
- inside and outside are shiny
- insulating foam

28

why do warm climate animals have large ears ?

increases SA so can radiate more heat

29

density =

mass / volume

30

what is buoyancy dependent on ?

whether the object is more/less dense than the fluid