What is the resistance when an object body is moved in contact with another object?

What simple machine is described as, "a circular device that is attached to a rigid bar in its center. A force applied to the wheel causes the axle to rotate, which can be used to magnify the force?"

Which simple machine is often considered a double inclined plane — both sides are inclined — that moves to exert a force along the lengths of the sides?

Which simple machine is a wheel with a groove along its edge, where a rope or cable can be placed?

What simple machine is described as, "a simple machine that consists of a rigid object (often a bar of some kind) and a fulcrum (or pivot)?"

What simple machine is described as, "a plane surface set at an angle to another surface. This results in doing the same amount of work by applying the force over a longer distance?"

Which simple machine is a sharp, pointed metal pin that has an inclined groove along its surface?

What is the ratio of the force exerted by a machine to the force applied to it.