Aman has a power of 90 w and mass 60 kg runs up a staircase in 40 s. if each staircase is 20cm high find the number of steps? (physics grade 9- gravitation)

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