Question

A cylinder, which is in a horizontal position, contains an unknown noble gas at 4.00 × 10 4 Pa 4.00×104 Pa and is sealed with a massless piston. The piston is slowly, isobarically moved inward 16.3 cm, 16.3 cm, which removes 1.50 × 10 4 J 1.50×104 J of heat from the gas. If the piston has a radius of 30.5 cm, 30.5 cm, calculate the change in the internal energy of the system Δ U ΔU .

Answer 1

Answer:

-13094.55179 J

Explanation:

Q = Heat = $-1.5\times 10^{4}\ J$

P = Pressure = $4\times 10^4\ Pa$

$\Delta V$ = Change in volume = $\pi r^2\times -h$(negative because it is decreasing)

h = Height = 16.3 cm

r = Radius = 30.5 cm

Entropy is given by

$\Delta U=Q-W$

Work done is given by

$W=P\Delta V\\\Rightarrow W=4\times 10^4\times (\pi 0.305^2\times -0.163)$

$\Delta U=-1.5\times 10^{4}-(4\times 10^4\times (\pi 0.305^2\times -0.163))\\\Rightarrow \Delta U=-13094.55179\ J$

The change in the internal energy of the system is -13094.55179 J