Question

The volume, v, of a certain gas varies inversely with the amount of pressure, p, placed on it. The volume of this gas is 175cm3 when 3.2cm2 of pressure is placed on it. What amount of pressure must be placed on 400cm3 of this gas?

Answer 1

v varies inverly as p is
v=k/p where k is a constant

given
v=175 and p=3.2
find k

175=k/3.2
times both sides by 3.2
560=k

v=560/p

for v=400, find p
400=560/p
times both sides by p
400p=560
divide both sides by 400
p=1.4

answer is 1.4cm² of pressure