Which of these waves cannot travel in a vacuum? (1 - microwave(2 - light wave(3 - sound wave(4 - electromagnetic wavebrainliest for correct!

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.

Which system of units is used by only a small number of countries in the world, including the u. s.

Madison lives near the ocean. she’s formed a hypothesis that increased concentrations of salt in the air speeds the corrosion of certain metals. if madison plans to test this hypothesis, she will have to deal with the following variables in her experiment: dependent variable: independent variable: one possible confounding variable: