A shock absorber is a mechanical device designed to smooth out or damp a sudden shock impulse and dissipate kinetic energy. It is analogous to a resistor in an electric RLC circuit. It is used to absorb or dissipate energy. Pneumatic and hydraulic shock absorbers commonly take the form of a cylinder with a sliding piston inside. Shock absorbers are an important part of automobile and motorcycle suspensions, aircraft landing gear, and the supports for many industrial machines.