物理

運動方程式

md2rdt2=Fm \dfrac{d^2 \boldsymbol{r}}{dt^2} = \boldsymbol{F}

$$ m \dfrac{d^2 \boldsymbol{r}}{dt^2} = \boldsymbol{F} $$

運動エネルギー

K=12mv2K = \dfrac{1}{2} m \|\boldsymbol{v}\|^2

$$ K = \dfrac{1}{2} m \|\boldsymbol{v}\|^2 $$

仕事とエネルギーの関係式

12mv212mv02=t0t1(mg)vdt\dfrac{1}{2}mv^2 - \dfrac{1}{2}mv_0^2 = \int_{t_0}^{t_1} (mg) \cdot vdt

$$ \dfrac{1}{2}mv^2 - \dfrac{1}{2}mv_0^2 = \int_{t_0}^{t_1} (mg) \cdot vdt $$

ラグランジュの運動方程式

ddt(Lq˙)Lq=0\dfrac{d}{dt} \left(\dfrac{\partial \mathcal{L}}{\partial \dot{q}} \right) - \dfrac{\partial \mathcal{L}}{\partial q} = 0

$$ \dfrac{d}{dt} \left(\dfrac{\partial \mathcal{L}}{\partial \dot{q}} \right) - \dfrac{\partial \mathcal{L}}{\partial q} = 0 $$

単原子分子理想気体

U=32nRTU = \dfrac{3}{2}nRT

$$ U = \dfrac{3}{2}nRT $$

状態方程式

pV=nRTpV = nRT

$$ pV = nRT $$

正弦波

y(x,t)=Asin{ω(txc)+α}y(x, t) = A \sin \{\omega \left(t - \dfrac{x}{c} \right) + \alpha \}

$$ y(x, t) = A \sin \{\omega \left(t - \dfrac{x}{c} \right) + \alpha \} $$

定常波

y(x,t)=2acos(2πxλ+α2α12)sin(2πft+α2+α12)y(x,t) = 2a \cos \left( 2 \pi \dfrac{x}{\lambda} + \dfrac{\alpha_2 - \alpha_1}{2} \right) \sin \left( 2 \pi ft + \dfrac{\alpha_2 + \alpha_1}{2} \right)

$$ y(x,t) = 2a \cos \left( 2 \pi \dfrac{x}{\lambda} + \dfrac{\alpha_2 - \alpha_1}{2} \right) \sin \left( 2 \pi ft + \dfrac{\alpha_2 + \alpha_1}{2} \right) $$

マクスウェル方程式

E=ρε0\nabla \cdot \boldsymbol E = \dfrac{\rho}{\varepsilon_{0}}

$$ \nabla \cdot \boldsymbol E = \dfrac{\rho}{\varepsilon_{0}} $$

×E=Bt\nabla \times \boldsymbol E = - \dfrac{\partial \boldsymbol B}{\partial t}

$$ \nabla \times \boldsymbol E = - \dfrac{\partial \boldsymbol B}{\partial t} $$

B=0\nabla \cdot \boldsymbol B = 0

$$ \nabla \cdot \boldsymbol B = 0 $$

×B=μ0i+1c2Et\nabla \times \boldsymbol B = \mu_{0}i + \dfrac{1}{c^2} \dfrac{\partial \boldsymbol E}{\partial t}

$$ \nabla \times \boldsymbol B = \mu_{0}i + \dfrac{1}{c^2} \dfrac{\partial \boldsymbol E}{\partial t} $$

ガウスの定理

VAdV=VAndS\iiint_{V} \nabla \cdot \boldsymbol A \, dV = \iint_{ \partial V} \boldsymbol A \cdot \boldsymbol n \,dS

$$ \iiint_{V} \nabla \cdot \boldsymbol A \, dV = \iint_{ \partial V} \boldsymbol A \cdot \boldsymbol n \,dS $$

シュレディンガー方程式

itψ(r,t)=(22m2+V(r,t))ψ(r,t)i \hbar \dfrac{\partial}{\partial t} \psi(r,t) = \left(- \dfrac{\hbar^2}{2m} \nabla^2+ V(r,t) \right) \psi(r,t)

$$ i \hbar \dfrac{\partial}{\partial t} \psi(r,t) = \left(- \dfrac{\hbar^2}{2m} \nabla^2+ V(r,t) \right) \psi(r,t) $$

ナビエ-ストークス方程式

ρ{vt+(v)v}=p+μ2v+ρf\rho \left\{\dfrac{\partial{\boldsymbol{v}}}{\partial{t}} + \left(\boldsymbol{v} \cdot \nabla \right) \boldsymbol{v}\right\} = -\nabla p + \mu \nabla^2 \boldsymbol{v} + \rho \boldsymbol{f}

$$ \rho \left\{\dfrac{\partial{\boldsymbol{v}}}{\partial{t}} + \left(\boldsymbol{v} \cdot \nabla \right) \boldsymbol{v}\right\} = -\nabla p + \mu \nabla^2 \boldsymbol{v} + \rho \boldsymbol{f} $$

Einsteinの重力波方程式

ϕμν=16πGc4Tμν\Box \phi_{\mu \nu} = - \dfrac{16 \pi G}{c^4} T_{\mu \nu}

$$ \Box \phi_{\mu \nu} = - \dfrac{16 \pi G}{c^4} T_{\mu \nu} $$