Answer:
An object is in motion if it changes position relative to a reference point.
Explanation:
The correct answer is D. I alread took this test.
The time for the echo to return is directly proportional to the distance. vw = fλ. In a given medium under fixed conditions, vw is constant, so that there is a relationship between f and λ; the higher the frequency, the smaller the wavelength.
Answer:
Althought it us possible to have more then one state, it's also possible to have only one state of matter
Explanation:
You can make solutions of only one state if matter, for example , it two liquids can be mixed to form a solution they are called miscible.
