Question 8 - Scientific Inquiry and Reasoning (Question Type) Practice Test for the MCAT

In an experiment to study frictional forces, a student attached a spring scale to identical bricks wrapped in different kinds of paper: brown paper, waxed paper and sand paper. Holding the spring scale, the student pulled the bricks across a table and measured the force required to pull the bricks across the table. The student wrapped the bricks in different paper to change the frictional forces between which two objects?