You need to know how much friction that object.
NO musical instrument produces a 'pure' tone with only a
single frequency in it.
EVERY instrument produces more or less harmonics (multiples)
in addition to the basic frequency it's playing.
The percussion instruments (drums etc) are the richest producers
of bunches of different frequencies.
Fuzzy electric guitars are next richest.
The strings and brass instruments are moderate producers of
harmonics ... I can't remember which is greater than the other.
Then come the woodwinds ... clarinet, oboe, etc.
The closest to 'pure' tones of single frequency are the sounds
made by the flute and piccolo, but even these are far from 'pure'.
The only way to get a true single-frequency sound is from an
electronic 'sine wave' generator.
Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by

For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
Search Results<span>By simply wrapping wire that has an electrical current running through it around a nail, you can make an electromagnet. When the electric current moves through a wire, it makes a magnetic field. ... You can make a temporary magnet by stroking apiece of iron or steel (such as a needle) along with a permanent magnet.
Hope This Helps!</span>
The answer is A- feeling a !etal wire get warmer as you roast a !arshmallow over a fire