The formula is:
W = p * ΔV, where W stays for work, p stays for the pressure and ΔV is the change of volume in the piston.
We know that : W = 0.6 J.
The piston has a diameter: 1.8 cm. It means that : r = 0.9 cm.
It travels 2.3 cm, so the height of a cylinder is: h = 2.3 cm.
ΔV = r² · π · h = 0.9² · 3.14 · 2.3 = 5.85 cm³ = 0.00000585 m³
The pressure:
p = W / V = 0.6 J / 0.00000585 m³ = 103,448.27 Pa
p = 103.45 kPa
Answer: The pressure of the steam is 103.45 kPa.