A student applies 55 N of force to a box on four types of surfaces. Each surface has a different value for Ffric- On which surface is the student not able to move the box?
A. A
B. C
C. D
D. B

Which of the following statements best distinguishes a hypothesis from a theory? a. theories are hypotheses that have been proved. b.hypotheses are guesses; theories are correct answers c. hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. theories are proved to be true; hypotheses are often contradicted by experimental results.