|
|
|
Message boards Post comment
|
List of equations in classical mechanics
This page gives a summary of important equations in classical mechanics.
Nomenclature
- a = acceleration (m/s2)
- F = force (N = kg m/s2)
- KE = kinetic energy (J = kg m2/s2)
- m = mass (kg)
- p = momentum (kg m/s)
- s = position (m)
- t = time (s)
- v = velocity (m/s)
- v0 = velocity at time t=0
- W = work (J = kg m2/s2)
- s(t) = position at time t
- s0 = position at time t=0
- runit = unit vector pointing from the origin in polar coordinates
- θunit = unit vector pointing in the direction of increasing values of theta in polor coordinates
Note: All quantities in bold represent vectors.
Defining Equations
Center of Mass
In the discrete case:
-
where is the number of mass particles.
Or in the continuous case:
-
where ρ(s) is the scalar mass density as a function of the position vector.
Velocity
-
-
Acceleration
- aaverage = Δv/Δt
- a = dv/dt = d2s/dt2
- |ac| = ω2R = v2 / R
(R = radius of the circle, ω = v/R [angular velocity])
Momentum
- p = mv
Force
- ∑F = dp/dt = d(mv)/dt
- ∑F = ma (Constant Mass)
Impulse
- J = Δp = ∫Fdt
- J = FΔt if F is constant
Moment of Intertia
For a single axis of rotation:
Angular Momentum
- |L| = mvr iff v is perpendicular to r
Vector form:
- L = r×p = Iω
(Note: I can be treated like a vector if it is diagonalized first, but it is actually a 3×3 matrix)
r is the radius vector
Torque
- ∑τ = dL/dt
- ∑τ = r×F
if |r| and the sine of the angle between r and p remains constant.
- ∑τ = Iα
This one is very limited, more added later. α = dω/dt
Precession
Energy
- ΔKE = ∫Fnet·ds
- KE = ∫v·dp = 1/2 mv2 if m is constant
- PEdue to gravity = mgh (near the earth's surface)
g is the acceleration due to gravity, one the physical constants.
Central Force Motion
Useful derived equations
Position of an accelerating body
- s(t) = 1/2at2 + v0t + s0 if a is constant.
Equation for velocity
- v2=v02 + 2a·Δs
Referenced By
Category:list | Classical Mechanics | List of Refernce Tables | List of intellectual/social/spiritual/artistic reference tables | List of list of pages | List of lists | List of lists of lists | List of physics topics F-L | List of reference tables | List of science topics | Lists | Newtonian Mechanics
|
|