Nhận biết (M1)

Friction, the force that resists the movement of two materials in contact with each other, exists even when the materials are static (not moving). Friction coefficients are values that represent the degree of resistance between materials, with smaller values indicating less resistance.

A student notes that of the pairs of materials in the graph, the greatest resistance occurs between __________

• A.

  graphite and steel.

• B.

  copper and cast iron.

• C.

  brass and steel.

• D.

  graphite and graphite.