John traveled on a motorbike a distance of 1,500 meters north to get to the nearest shopping center. he then turned back south and rode another 1,450 meters to meet his friend. what was his displacement?

What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?

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

What is the relationship between wavelength of light and the quantity of energy per photon?