Answer: Vibrating
Explanation:
Sound is produced when an object vibrates. The sound vibrations cause waves of pressure that travel through a medium, such as air, water, wood or metal. Sound is a form of mechanical energy.
To solve this problem we will apply the concept related to destructive interference (from the principle of superposition). This concept is understood as a superposition of two or more waves of identical or similar frequency that, when interfering, create a new wave pattern of less intensity (amplitude) at a point called a node. Mathematically it can be described as

Where,
d = Path difference
= wavelength
n = Any integer which represent the number of repetition of the spectrum
In this question the distance between the two source will be minimum for the case of minimum path difference, then n= 1



Therefore the minimum distance that should you separate two sources emitting the same waves is 2.5mm
It should be at about 65J. Not sure, hope I helped.
Answer:
7.5
Explanation:
The dielectric constant of ceramics is about 7.5.
The dielectric constant of a substance is the ratio of the electric permeability of a substance to the electric permeability of free space.
Dielectric constant gives a good overview about the ability of substance to store charges compared to another.
Most substances have their electric constant and they suggest the ease by which they can store electrical energy. This is very important in developing capacitors.