What does the strength of friction depend on?
A. The direction of the forces.
B. The types of surfaces and how hard the
mbjects are being pushed.
C. The color of surfaces and how hard they push.
D. Only how hard the objects are being pushed.

the direction of force.

rocks and weathering-matching

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.