Answer
(a) The oxygen would occupy a volume of $2.56~m^3$ at atmospheric pressure.
(b) The cylinder of oxygen will last for $320~minutes$
Work Step by Step
(a) We can use Boyle's law to find the volume at atmospheric pressure:
$P_2~V_2 = P_1~V_1$
$V_2 = \frac{P_1~V_1}{P_2}$
$V_2 = \frac{(15.2\times 10^6~Pa)(0.0170~m^3)}{1.01\times 10^5~Pa}$
$V_2 = 2.56~m^3$
The oxygen would occupy a volume of $2.56~m^3$ at atmospheric pressure.
(b) We can convert the volume at atmospheric pressure to units of liters:
$2.56~m^3 \times \frac{10^3~L}{1~m^3} = 2.56\times 10^3~L$
We can find the time that the oxygen lasts:
$t = \frac{2.56\times 10^3~L}{8.0~L/min} = 320~min$
The cylinder of oxygen will last for $320~minutes$