Answer: For objects that move in fluids such as boats, planes, cars, etc the shape of their body is simplified in order to reduce the friction between the body of the objects and the fluid.
By polishing the surface, polishing makes the surface smooth and friction can be reduced.
Using lubricants such as oil or grease can reduce the friction between the surfaces.
When objects are rolled over the surface, the friction between the rolled object and the surface can be reduced by using ball bearings.
Explanation:
