Two boxes are connected by a string. The first box has a mass of 4.2 kg and the second 2.8 kg. A string attached to the first box pulls horizontally with a force of
7.5 N. Calculate the tension in the second string if the force of friction on the first
box is 2.0 N and the force of friction on the second is 1.6 N.

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve