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

-13094.55179 J

Step-by-step explanation:

Q = Heat =
`-1.5* 10^(4)\ J`

P = Pressure =
`4* 10^4\ Pa`

`\Delta V` = Change in volume =
`\pi r^2* -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* 10^4* (\pi 0.305^2* -0.163)`

`\Delta U=-1.5* 10^(4)-(4* 10^4* (\pi 0.305^2* -0.163))\\\Rightarrow \Delta U=-13094.55179\ J`

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