Answer: The pressure is 3 units (La presión es 3 unidades)
Step-by-step explanation:
This can be translated to:
"According to Boyle's law, the pressure is inversely proportional to the volume that contains a certain amount of gas. What pressure is a gas subjected to, if by increasing this pressure by 7.5 the volume varies by 5/7 of its value?"
Boyle's law says: P*V = ct
If initially we have
P1 and V1
and finally we have
P2 and V2
we know that:
P2 = P1 + 7.5
V2 - V1 = 5/7V1
V2 = 2/7V1
then we can imput those things i the Boyle's law:
P1*V1 = P2*V2 = (P1 + 7,5)*(2/7)*V1
we divide by V1 in both sides:
P1 = (P1 + 7,5)(2/7)
(7/2)*P1 = P1 + 7,5
P1(7/2 - 1) = 7,5
P1(5/2) = 7,5
P1 = (2/5)*7,5 = 3