Foundations

Question 1

Bulk Matter

Answer 1

consists of large number of atoms molecules or ions,

Question 2

Properties of bulk matter

Answer 2

the state of a sample of matter is defined by specifying the values of various properties. Among them are

mass

volume

amount of substance

Question 3

Translation

Answer 3

the motion of a particle through space

Question 4

Velocity

Answer 4

the rate of change of its position

v=dr/dt

Question 5

Linear momentum

Answer 5

of a particle of mass m is related to its velocity,v , by

p=mv

Question 6

angular momentum J

Answer 6

the rotational motion if a particle about a central point

J=Iω

ω-angular velocity

I-moment of inertia

Question 7

Moment of Inertia

Answer 7

a measure of a bodys resistance to rotational acceleration

I=mr²

Question 8

Newton’s 2nd law

Answer 8

the rate of change of momentum is equal to the force acting on the particle

dp/dt=F

Question 9

Newtons

Answer 9

1 N = 1kgms^-2

Question 10

torque

Answer 10

a twisting force

T=dI/dt

Question 11

Work

Answer 11

is done in order to achieve motion against an opposing force

• dw = -F*ds*
• F*ds=F_xdx + F_ydy + F_z*

Question 12

Energy

Answer 12

is the capacity to do work

Question 13

Joule

Answer 13

1 J= 1N*m=1 kg m² s^-2

Question 14

Power

Answer 14

the rate of supply of energy

1 W = 1 J s^-1

Question 15

kinetic energy

Answer 15

of a body is the energy the body possesses as a result of its motion

E_k = 1/2 mv² = F²t²/2m

Question 16

Potential Energy

Answer 16

of a body is the energy it possesses as a result of its position

Question 17

total energy

Answer 17

of a particle is the sum of its kinetic and potential energies

Question 18

Coulomb potential energy

Answer 18

the potential energy between two electrons charges

Question 19

Thermodynamics

Answer 19

the systemic discussion of the transfer and transformation of energy in bulk matter

Question 20

internal energy

Answer 20

total energy of a system

Question 21

1st Law

Answer 21

states that the internal energy is constant in a system isolated from external influences

the internal energy of a sample of matter increases as its temperature is raised

ΔU = CΔ​T

Question 22

Entropy

Answer 22

S, is a measure of the measure of the quality of the energy of a system

Question 23

2nd Law of thermodynamics

Answer 23

states that any spontaneous (that is, natural) change in an isolated system is accompanied by an increase in the entropy of a system

the natural direction of change is accompanied by dispersal of energy from a localized region or its conversion to less organized from

Question 24

Gibbs free energy

Answer 24

is a measure of the energy stored in a system that is free to do useful work

is at a minimum when temperature and pressure are constant

Question 25

quantized

Answer 25

restricted to certain discrete values

theses permitted energies are called energy levels

allowed energies are widest apart - for particles of small mass confined to small regions of space

quantization is very unimportant for macroscopic bodies and very important for electrons in atoms and molecules

G = H - TS

Question 26

Boltzmann distribution

Answer 26

N_i/Nj = e^-(ε​_i-ε_j)/kT

Question 27

Average speed of molecules

Perfect gas

Answer 27

v_mean =(8RT/πM)^1/2

Question 28

Wavelength

Answer 28

the distance between the neighbouring peaks of the wave

Question 29

frequency

Answer 29

the number of time per secound at which its displacement ae a fixed point returns to its original value

Question 30

electromagnetic field

Answer 30

an oscillating electric and magnetic disturbance that spreads as a harmonic wave through space

Question 31

electric field

Answer 31

act on charged particle (whether stationary or moving)

Question 32

magnetic field

Answer 32

acts only on moving charged particles