Question

Friction is proportional to
A) Normal force
B) Gravitational force
C) Applied force​

Answer 1

Answer:

gravitational force

Explanation:

take Care ur self from this dangerous situation

Answer 2

Answer:

Physics is first an observational science. Friction proportional to normal force is a model that describes an observation. First you measure frictional force and normal force for a wide range of forces and between a large variety of surfaces. Then for each pair of surfaces you plot the relationship between the two forces and observe that the relationship is well described by a straight line. You then adopt the model that the friction force is proportional to the normal force as part of your description of how two objects interact while in contact.

The above is possible without any knowledge of how surfaces actually interact with each other, which may be extremely complex and difficult to model. It also doesn’t easily capture small deviations from the proportional model without extremely careful measurements. It also potentially makes completely wrong predictions. The model is typically extrapolated to any two surfaces in contact, but it’s possible that for some pairs of materials, friction is not proportional to normal force, but we didn’t include those in the above observation.