What is a wedge? Explain the principle on which it works by giving suitable examples.

Hint-A wedge is a simple machine consisting of a pointed or sharp edge. It contains inclined planes which taper to form a sharp edge. Wedges are primarily used for splitting or cutting things.

Complete step by step solution:
The machines with few or no moving parts to modify motion and force for doing work are called simple machines. The simple machines include lever, inclined plane, wheel and axle, wedge, pulley and screw.

Wedge is a simple machine in which two inclined planes are joined together to form a sharp edge. An object that tapers to a thin edge can be called a wedge.
The common shape of a wedge is shown below.

When we push a wedge in one direction force is created in the sideways directions. Metal or wood is usually used for making wedges. It can be used for splitting, lifting, tightening or for securing a hammerhead on its handle. During the prehistoric times wedge was used for splitting rocks.
The principle on which a wedge works is the principle of an inclined plane.
An inclined plane is a sloping surface in which a small force acting along the slope can produce a larger force. That is why we are able to split hard objects using wedges.
So, in general we can define wedge as a double inclined plane with two sloping surfaces that taper to form a sharp edge. The common examples of wedges that we use are knives, axes, chisels etc. Wedge can also be formed by using a number of inclined planes such that we get a pointed edge. The sloping surfaces will taper to form a very sharp pointed edge which can either split or pierce a material. The examples of such pointed wedges are pins, nails, needles etc. The shape of the front part of a boat is also shaped like a wedge. This is because we know that wedge is primarily used for cutting or splitting things. The wedge-shaped front of the boat will help it to cut across the flowing water.

Note:The shape of the front part of a boat is also shaped like a wedge. This is because we know that wedge is primarily used for cutting or splitting things. The wedge-shaped front of the boat will help it to cut across the flowing water. We can think of a screw also as an example of wedge by thinking of it as a wedge wrapped around a cylinder.