A ferry is crossing a river. The ferry is headed due north with a speed of 1.7 m/s
relative to the water and the river’s velocity
is 4.8 m/s to the east.
What is magnitude of the boat’s velocity relative to the earth
answer in units of m/s

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