A boy on earth weighs 400 N. What is his mass? A. 40.8 kg B. 400 kg.
C. 30.4 kg
D. 0.02 kg

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