Real world examples of mechanical force?

Answer 1

-- pistons pushing a drive shaft around
-- drive shaft pushing wheels around
-- tire treads pushing against the ground
-- pushing bicycle pedals
-- shoe-soles pushing back against the ground
-- seat of a chair pushing up against one's butt
-- twisting a door-knob
-- pushing the button of a pen down to extend the point
-- rotating the spoon to mix the coffee in the cup
-- closing the jaw to shred the bite of meat
-- rotating the wrench to tighten the nut
-- squeezing the handles together to crack the nut
-- pushing the key down to type the character
-- pushing the mouse finger down to make the click
-- pushing the DTMF button down to 'dial' the number
-- lifting the flat part of the buckle to release the seat belt
-- pulling the rope to raise the flag
-- lifting the shovel to move the snow
-- pulling the string to untie the shoe
-- pushing the mower to move to another patch of grass

There are probably a few more.