thermal physics chapter 14

Question 1

What is thermal equilibrium

Answer 1

the point at which there is no net thermal energy transfer between two objects, as they are at the same temperature

Question 2

the thermodynamic scale vs celsius

Answer 2

Celsius is based on boiling and melting point of water, which are not constant at different temperatures
Kelvin is based on triple point of pure water and absolute zero, which are constant
k

Question 3

K =

Answer 3

c + 273 (approx.)

Question 3

simple kinetic model for solids

Answer 3

particles are tightly packed in fixed positions with strong electrostatic forces of attraction between atoms have a high potential energy(which is negative) and have some kinetic energy so they vibrate about a mean position

Question 4

gas

Answer 4

high kinetic energy potential energy is negligible and 0 , the particles move with random speed and direction

Question 4

liquid

Answer 4

particles still have strong electrostatic forces of attraction but not as strong but a greater mean separation. are not fixed and free to move around another because they have more kinetic energy

Question 5

when the temperature of a body rises

Answer 5

its internal energy increases as kinetic energy increases. when the state changes the kinetic energy is constant and the potential energy increases as the thermal energy is used to overcome electrostatic bonds

Question 6

what is Brownian motion

Answer 6

the idea that matter made made of millions of tiny particles which exhibit random motion in random directions with random velocity due to transfers of momentum from collisions with the particles of the air

Question 7

how to demonstrate Brownian motion

Answer 7

use a microscope pointed at a smoke cell with a lamp so that the smoke particles scatter the light. Now the smoke particles can be observed to move about randomly due to collisions with the air particlesd