In many cases, some combinations of simple machines are used to perform the work in a more efficient manner. For example, when a person strikes a wooden block with an ax, the blade acts like a wedge, whereas, our arm acts like a lever. There are six basic types of these machines:
- Wheel and Axle
- Inclined Plane
The following paragraphs explain the working mechanism of a wedge, along with its examples and applications.
The first substantial use of this simple machine is controversial; evidences suggest that many wedge-like objects were utilized in ancient Egypt to build structures like the Pyramids and Sphinx. Apart from rocks and stones, animal horns and antlers, tree branches, and sharpened metal were also used for several purposes. Over time, other types of wedges, like blades, swords, chisels, nails, scissors, door stoppers, etc., were developed and used.
P = Fi × Ci = Fo × Co
As other forces are absent, the ratio of the forces is equal to the ratio of their velocities:
Fo ÷ Fi = Ci ÷ Co
As both the velocities are perpendicular to each other, they can be said to be constant for specific force ratios. Hence, the output velocity can be written as:
Co = Ci × tanϴ
where 'ϴ (theta)' is the wedge angle, along which the force is applied.
The force ratio that refers to the mechanical advantage is given below:
Fo ÷ Fi (MA) = 1 ÷ tanϴ
This is called the mechanical advantage (MA) of the wedge, and it mainly denotes the amount of effort needed to perform the work.
The Ideal Mechanical Advantage (IMA) is represented as the ratio of the wedge length to the wedge width, and is illustrated in the image given below:
Here, Wl is the length of the wedge from the sharp surface to the blunt portion, and Wb is the breadth or width of the device across the blunt surface. The IMA is calculated when additional external forces like friction are also present. The length can also be called the penetration depth, which indicates how deep the device can go inside an object.
The effort required to split or lift an object using the wedge is inversely proportional to the length, and directly proportional to its width.