If the vertical displacement from crest to trough is 0.50 cm, what is the amplitude?

1 cm

.5 cm

.25 cm

We have a colorless transparent liquid. it looks like water. we seperated it into a solid and a liquid by evaporration and condention was this a chemichal or a physical seperation a. chemical seperation b. physical seperation

Why do astronauts in the space shuttle weigh less?

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?