Boyle's law states:
pV = C, where p = pressure, V = volume, C = constant.
Therefore,
p1V1 = p2V2
And the,
p2 = p1V1/V2
p1 = 512 kPa
V1 = 5l
p2 =?
V2 = 4l
Therefore,
p2= 512*5/4 = 640 kPa
Energy=mass*SHC*temp change
=100*0.9*75
=6750J
They can be the same shape & size but they can have different mass. And mass is density so if they have different masses then they have different densities.
MASS=DENSITY
The correct answer is conner because he has more than everyone else 4 is more than 3.5, 2.5, and 3