EmeraldWonder

Friction is the static electricity of two things that are rubbed against each other. The highest coefitient of friction will be rubber and dry concrete. Because the highest coefitioent of friction is that the two surfaces in contact have a greater resistance.

So the answer would be 

D. Rubber on dry concrete

Hope this helps ;P

Friction between solids can be most accurately defined as the force that opposes the sliding motion of two surfaces that are touching each other. It does not enhance the sliding motion. 

The answer is

False

Hope this Helps ;P

True was answered yesterday.

Its not A because or resistance is the force of an object passing through air. 

Its not B because kenetic is the energy in motion. 

Its not C because fluid force is the force of water on an object.

Its D because static friction is when one object is on top of another or resting. Which can be two seperate surfaces. And they can be divided into two categories. Also D if you are asking for 1 answer.

But if you are asking for the two most common types of friction, its static and kenetic. Because friction between two flat surfaces is either static or kenetic friction.

Hope this helps ;P

Ugghhhh. You say it from experience.