If the form of a sound wave traveling through air is s(x, t) = (7.0 nm) cos(kx + (3000 rad/s)t + φ), how much time does any given air molecule along the path take to move between displacements s = +2.1 nm and s = -2.1 nm?

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i think they are all correct

explanation:

they seem good

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2