Answer:
Option (3)
Explanation:
Wind energy is directly derived from the wind. In the places where wind blowing is quite frequent, there wind mills are being set up, and the turbines in it rotates due to the prevailing wind. Due to this continuous motion of turbines, it collects the wind energy and it is being transferred into electrical energy.
It is cost-effective and does not produce any kind of pollution and is completely a renewable energy, that it can generated again and again.
It does have certain drawbacks also, because <u>the area may sometime do not experience constant wind, due to which it cannot store energy. So frequent wind blowing areas are the best place to set up windmills</u>.
Thus, the correct answer is option (3)
Answer:
Yes, I would be able to hear the speaker clearly because the supposedly dropping off of sound as the distance gets farther is counteracted by "reverberations" inside the auditorium.
Explanation:
According to the "Inverse Square Law," if the distance from the sound source is doubled, the intensity of the sound will diminish by 6 decibels. This is true if the situation is in a <em>"free field,"</em> which means the sound has no reflection.
However, this is not the case in an "auditorium." An auditorium causes the <u>"reverberation" of sound. </u>This prolongs the resonance of the sound. So, this means that even if the sound drops off by a factor of 100 (20 decibels), due to reverberations, the height of the ceiling, the kind of wall and materials used in making the seats also affect the intensity of the sound waves. This is the reason why auditoriums are used as venues for <em>concerts, presentations and the like</em> where a <u>large group of people serve as the audienc</u>e.
Answer:
CH4 + 2 O2 → CO2 + 2 H2O
Explanation:
There are one mole of O2 on the left side and on the right side there are three moles of O2. And to fix it you would need to make it two moles of O2 to have four molecules of O2 on the left side. Then you would make two moles of H2O to have a total of four moles of O2 on the right. Therefore, CH4 + 2 O2 → CO2 + 2 H2O is the answer.