If the particles of the medium are vibrating to and fro in the same direction of energy transport, then the wave is a wave.

What is created when solids,liquids,an gases mix with one another

Which word expression describes how much to calculate pressure

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.