= t(Vf + Vi/2)
<span>Vf + Vi/2 = d/t </span>
<span>Vf = (d/t) - Vi/2 </span>
<span>Answer: Vf = (d/t) - Vi/2 OR (2dt - Vit)/2t
</span>
Answer: Option (A) is the correct answer.
Explanation:
When more and more energy is provided to a gas then its atoms move more rapidly.
This rapid and continuous movement converts the gas into hot ionized ions which have positively charged ions and negatively charged electrons.
Therefore, we can conclude that as the atoms move faster, the gas can change into a plasma.
Power is the work performed divided by time in seconds. The work is the force times distance:

the time in seconds is 60*11+30=690s so the power is

So choice B