I have the same question right now and i think that it is D
You would use the formula for Boyle's Law:
(P1) (V1) = (P2) (V2)
(101.5) (2.0) = (P2?) (.75)
*P2 = 270kPa (You're allowed 2 significant figures)
P = Pressure
V = Volume
Depending in the category of the Hurricane, you make experience different levels of wind power and destruction. Hurricanes only have 5 categories ranking from Category 1 to Category 5. The smallest category is category 1 making category 5 the largest. The bigger the category, the more wind or destruction you'll experience.
In the context of chemistry, yes. Energy input is always equal to the energy output.
