Physically Powered Motor
Some motors are powered by potential or kinetic energy, for example some funiculars, gravity plane and ropeway conveyors have used the energy from moving water or rocks, and some clocks have a weight that falls under gravity. Other forms of potential energy include compressed gases (such as pneumatic motors), springs (clockwork motors) and elastic bands.
Historic military siege engines included large catapults, trebuchets, and (to some extent) battering rams were powered by potential energy.
Read more about this topic: Engine
Famous quotes containing the words physically and/or motor:
“... word-sniffing ... is an addiction, like glue—or snow—sniffing in a somewhat less destructive way, physically if not economically.... As an addict ... I am almost guiltily interested in converts to my own illness, and in a pinch I can recommend nearly any reasonable solace, whether or not it qualifies as a true descendant of Noah Webster.”
—M.F.K. Fisher (1908–1992)
“We disparage reason.
But all the time it’s what we’re most concerned with.
There’s will as motor and there’s will as brakes.
Reason is, I suppose, the steering gear.”
—Robert Frost (1874–1963)