Energy travels with sound waves.
The pet store would be the reference point because it is where he started and it will not move. Hope this helped.
Answer:
The objects kinetic energy increases as it falls from some height.
The first sentence is a chemical change because it is two component's that when mixed together you make bubbles and the second one is physical because you are making the bubbles cause just setting the straw in there is just doing nothing
Newton's law of universal gravitation<span> states that a particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. hope this helps =)</span>