Power

$P$ $\mathrm{W}$ power
$\eta$   efficiency
$W$ $\mathrm{J}$ work
$E$ $\mathrm{J}$ energy
$F$ $\mathrm{N}$ force
$v$ $\mathrm{m/s}$ velocity
$s$ $\mathrm{m}$ distance, way travelled
$t$ $\mathrm{s}$ time

Leistung

$$ P = \frac{\mathrm{d}W}{\mathrm{d}t} \qquad
P = \vec{F} \, \frac{ \mathrm{d}\vec{s}}{\mathrm{d}t} \qquad
P = \vec{F} \, \vec{v} $$

Mittlere Leistung

$$ P_m = \frac{W_{tot}}{t_{tot}} $$

Wirkungsgrad

$$ \eta = \frac{W_{out}}{W_{in}} \qquad
\eta = \frac{E_{out}}{E_{in}} \qquad
\eta = \frac{P_{out}}{P_{in}} $$

$$ \eta = \frac{ \displaystyle{ \int\limits_0^{t_{in}} \! P_{out} \;\mathrm{d}t } }{ \displaystyle{ \int\limits_0^{t_{in}} \! P_{in} \;\mathrm{d}t } } \qquad
\eta = \prod_{i=1}^n \eta_i = \eta_1 \; \eta_2 \; \eta_3 \; \ldots $$