Answer:
Sound can't travel in a vaccum.
Explanation:
Sound waves need a medium in order to travel (e.g. air, water, glass)
Since there was a vaccum between the glass the sound couldn't travel since vaccum's contain a very small amount of atoms.
I believe a physical change is one where the physical makeup of a substance is altered as opposed to a chemical change or molecular one which happens on a smaller scale. This would make me think that B. metal denting is accurate since all the other options are examples of chemical or molecular changes. A is an example of a liquid turning into a gas, which is a molecular change. The other two are chemical changes. Hope this is correct.
Answer:
64 ohms =R
Explanation:
R is directly proportional to V
R is inversely proportional to I(Current
Harmonics, Loop and Harmonic number
Hope this helps :)