Physical Quantities
Quantity | Definition | Formula | Units | Dimensions | |
---|---|---|---|---|---|
M
___ |
Length or Distance | fundamental | d | m (meter) | L (Length) |
Time | fundamental | t | s (second) | T (Time) | |
Mass | fundamental | m | kg (kilogram) | M (Mass) | |
Area | distance2 | A = d2 | m2 | L2 | |
Volume | distance3 | V = d3 | m3 | L3 | |
Density | mass / volume | d = m/V | kg/m3 | M/L3 | |
Velocity | distance / time | v = d/t | m/s | L/T | |
Acceleration | velocity / time | a = v/t | m/s2 | L/T2 | |
Momentum | mass ×velocity | p = mv | kg·m/s | ML/T | |
Force Weight |
mass ×acceleration mass ×(accel. of grav.) |
F = ma W = mg |
N (newton) = kg·m/s2 | ML/T2 | |
Pressure or Stress | force / area | p = F/A | Pa (pascal) = N/m2 = kg/(m·s2) | M/LT2 | |
Energy or Work Kinetic Energy Potential Energy |
force ×distance mass ×velocity2 / 2 mass ×(accel. of grav.) ×height |
E = Fd KE = mv2/2 PE = mgh |
J (joule) = Nm = kg·m2/s2 | ML2/T2 | |
Power | energy / time | P = E/t | W (watt) = J/s = kg·m2/s3 | ML2/T3 | |
Impulse | force ×time | I = Ft | N·s = kg·m/s | ML/T | |
Action | energy ×time momentum ×distance |
A = Et A = pd |
J·s = kg·m2/s | ML2/T | |
A
___ |
Angle | fundamental | θ | ˚(degrees) or rad (radians) 360˚= 2π rad |
dimensionless |
Cycles | fundamental | n | cyc (cycles) | dimensionless | |
Frequency | cycles / time | f = n/t | Hz (hertz) = cyc/s = 1/s | 1/T | |
Angular Velocity | angle / time | ω = θ/t | rad/s = 1/s | 1/T | |
Angular Acceleration | angular velocity / time | α = ω/t | rad/s2 = 1/s2 | 1/T2 | |
Moment of Inertia | mass ×radius2 | I = mr2 | kg·m2 | ML2 | |
Angular Momentum | radius ×momentum (mom. of inert.) ×(ang. vel.) |
L = rp L = Iω |
kg·m2/s | ML2/T | |
Torque | radius ×force (mom. of inert.) ×(ang. accel.) |
T = rF T = Iα |
N·m = kg·m2/s2 | ML2/T2 | |
T ___ |
Temperature | fundamental | T | ˚C(celsius) or K (kelvin) | K (Temp.) |
Heat | heat energy | Q | J (joule) = kg·m2/s2 | ML2/T2 | |
Entropy | heat / temperature | S = Q/T | J/K | ML2/T2K | |
E
|
Electric Charge (+/-) | fundamental | q | C (coulomb) | C (Charge) |
Current | charge / time | i = q/t | A (amp) = C/s | C/T | |
Voltage or Potential | energy / charge | V = E/q | V (volt) = J/C | ML2/CT2 | |
Resistance | voltage / current | R = V/i | Ω (ohm) = V/A | ML2/C2T | |
Capacitance | charge / voltage | C = q/V | F (farad) = C/V | C2T2/ML2 | |
Inductance | voltage / (current / time) | L = V/(i/t) | H (henry) = V·s/A | ML2/T2 | |
Electric Field | voltage / distance force / charge |
E = V/d E = F/q |
V/m = N/C | ML/CT2 | |
Electric Flux | electric field ×area | φE = EA | V·m = N·m2/C | ML3/CT2 | |
Magnetic Field | force / (charge ×velocity) | B = F/qv | T (tesla) = Wb/m2 = N·s/(C·m) | M/CT | |
Magnetic Flux | magnetic field ×area | φM = BA | Wb (weber) = V·s = J·s/C | ML2/CT |
Mass, energy, momentum, angular momentum, and charge are conserved, which means the the total amount doesn't change in an isolated system.
거리(길이)[m], 시간[s] , 질량[kg]
속도[m/s]=거리[m]/시간[s] *거리(위치의 변화)
속력(속도의 크기)
가속도[㎨]=속도의 변화[m/s]/시간[s]
운동방정식 ; 힘[kg×m/s2 ]=질량[kg]×가속도[m/s2 ]
[kg×m/s2 ]=[N](뉴턴)
운동량[kg×m/s ]=질량[kg]×속도[m/s]
충격량[N×s]=힘[N]×시간[s]
[N×s]=[kg×m/s2 ×s]=[kg×m/s ]
일[N×s]=힘[N]×거리[m]
[N×s]=[kg×m2 /s2 ]=[J](줄)
운동에너지 ;[kg×m2 /s2 ]=1/2×질량[kg]×(속도)2[(m/s)2 ]
[kg×m2 /s2 ]=[J](줄)