The force that opposes the motion of an object through a fluid is known as fluid friction. This type of friction occurs when an object moves through a fluid, such as air or water, and experiences resistance to its motion. Fluid friction is influenced by factors like the speed of the object, the viscosity of the fluid, and the surface area of the object in contact with the fluid.
Examples of fluid friction include the resistance felt when moving a hand through water or when a car moves through the air. This force can be reduced by changing the shape of the object to minimize contact with the fluid or by using lubricants to decrease the friction between the object and the fluid.
In the context of the given options:
- a) Rolling friction: This type of friction occurs when an object rolls over a surface.
- b) Static friction: This type of friction prevents an object from moving when a force is applied.
- c) Net force: The overall force acting on an object, considering all forces involved.
- d) Fluid friction: The force that opposes the motion of an object through a fluid.
Therefore, the correct answer to the question is d) fluid friction, as it specifically addresses the resistance encountered when an object moves through a fluid.