The maximum kinetic energy of the electron emited from a metallic surface is 1.6x10 to the power -19 J when the frequency of radiation is 7.5 × 10 to the power-14 Hg. calculate of minimum frequency of radiation for which radiation is emited

Ais not a compound machine. a. bolt b. shovel c. handcart (dolly) d. see-saw (teeter totter)

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

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