How is power applied to the wedge?
Power is applied to the wedge by means of sudden blows from a hammer.
What prevents the wedge from flying back after the blow?
The friction between the wedge and the other body, keeps it from flying back.
What instruments are made in the form of a wedge?
Knife-blades, hatchets, axes, razors, and cutting instruments of nearly all kinds, are in the form of the wedge.
Screw.
What is a screw?
A screw is another form of the inclined plane.
Where is the inclined plane on a screw?