Question

A high pressure gas inflates a balloon, doing 103 joules of work. It happens quickly enough that any heat exchange is negligible.

What is the change in the system’s internal energy? How much energy is transferred to the system as heat?

Identify the thermodynamic process.

Answer 1

∆U = -103 joules

Process: adiabatic

Step-by-step explanation:

Given: W = 103 J

Find: internal energy, ∆U; heat, Q

No heat transfer occurs, so Q = 0

∆U = Q – W

∆U = -W

∆U = -103 joules

Process: adiabatic

Answer 2

Change in system's internal energy ΔU = 103 joules.

Adiabatic process as Q(heat exchange) = 0.

Step-by-step explanation:

From, first law of thermodynamics,

Heat energy given to system = change in internal energy + work done by system

⇒ Q = ΔU + W.

here, given that heat exchange is negligible,⇒ Q =0 .

work is done on the system, ⇒W = -103 joules

⇒ ΔU = Q - W = 0 -(-103) = 103 Joules.

This process, where there is no heat exchange is adiabatic process.