Answer: 3 The string should be loosened because the frequency of the string is 5 Hz above the correct frequency.
Explanation: In order to explain this problem we have to consider the relationship bewteen the Tension and the frequency, this is given by:
We know that:
where μ and T are the mass linear density and Tension of teh string, respectively.
We also know that v=λ*ν the speed is related to the wavelength (λ) and the frequency (ν).
Then we have that frequency depents directely of the Tension (T) on the string.
In our case the frequency to be tuned is 3 Hz, firstly the piano tuner slightly tightening then he hears 5 beats per second (5 Hz). Then it is neccesary loose the tension on the string because the actual frequency is above to the correct frequency (3 Hz).
Answer:
Option B) The fuel for nuclear fusion comes from sea water
Explanation:
Nuclear fusion can not be carried out by using any type of water as water is composed of stable water molecules ( which is quite difficult to be decayed by any simple method.
Moreover, fusion reactions demands the combination of nuclei of lighter elements for which it makes use of the heavy isotopes of Hydrogen that are Deuterium and Tritium as fuel to carry out the nuclear fusion.