pure capacitance
stiffness
damping

контекст такой

(The charge on the capacitor is q and the voltage
across the plates is e; the displacement of the movable plate is x and the
external force required to hold the movable plate in equilibrium against
the electrostatic attraction force is f. )

The electromechanical transducer is assumed to be perfect, meaning that the electrical side is a pure capacsitance, and the mechanical construction is massless and without stiffness or damping.

Заранее спасибо!

Если эти фразы для Вас сложны, дальше будет еще хуже:((

imho