Friction can be reduced by changing from
A. sliding to rolling
B. rolling to sliding
C. potential energy to kinetic energy
D. dynamic to static
Answer: A
Source:
Reducing friction
Devices such as wheels, ball bearings, roller bearings, and air cushion or other types of fluid bearings can change sliding friction into a much smaller type of rolling friction.
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
There are several types of friction:
- Dry friction resists relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving surfaces.
- Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other.
- Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces.
- Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body.
- Internal friction is the force resisting motion between the elements making up a solid material while it undergoes deformation.