Question

A streamlined body:

Answer 1

Hint: In this question, we will see the basics of a streamlined body and its importance. This will directly give us the required result. Also, we will study about the basics of friction and the types of friction, for our better understanding.

Complete answer:
As we know that a streamline body is a shape such that it helps to reduce the friction between a fluid and an object moving through that fluid.
Further, Drag is defined as a force that slows down motion. Friction drag is a special kind of a drag. Friction drag occurs when the fluid closest to the object or the body sticks to its surface, exerting a force that opposes the motion of the object.
Here, many animals, such as birds and dolphins, and also many machines, like airplanes and submarines, have streamlined bodies to reduce friction drag as they move through air or water.
Therefore we can say that a streamlined body reduces the friction.

Additional information:
As we know that the friction force can be defined as the force exerted by a surface when an object moves across it or even makes an effort to move across the surface. There are three types of friction force - sliding friction, rolling friction and static friction. It can be said that the friction force often opposes the motion of an object.
Static friction comes into action on objects when they are resting on a surface. For example, if we are hiking in the woods, there is a presence of static friction between our shoes and the trail each time we put down our foot. Without this friction, our feet would slip out and thereby, making it difficult to walk.
Sliding friction is friction that comes in action on objects when they are sliding over another surface. As we know that the sliding friction is weaker than the static friction. That is the reason that it is easier to slide a piece of furniture over the floor after we start it moving than it is to get it moving in the first place.
The last one is rolling friction is friction that comes in action on objects when they are rolling over another surface. Rolling friction is much weaker than sliding friction and static friction. This is the reason that most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards, as these wheels make it easier to travel with facing less frictional force.

Note:
Frictional force is a force that opposes the motion of any object. There are many practical examples of frictional force. We should also remember that various kinds of lubricants are used to overcome the frictional force like- grease, oil etc.