Question

An automobile engine provides 632 Joules of work to push the pistons and generates 2203 Joules of heat that must be carried away by the cooling system. Calculate the change in the internal energy of the engine. E

Answer 1

Answer / Explanation

To properly solve this question, we recall the second law of thermodynamics which sates that processes that involve the change, transformation or conversion of hear or energy is irreversible.

Recalling the aforementioned and referencing the question asked, we then know that:

δQ = dU + δA

Where:

δQ = change in heat of a given system

δA = Work done on or by the system

dU = Change in the internal energy of the given system

Solving further, we have:

δQ = dU + δA

Inserting the values from the questions representing the variables, e then have:

δQ = dU + δA

Now making dU the subject of formula since that is what we are looking for:

We then have:

dU = δQ - δA

dU = 2203 - 632

dU = 1571 joules

Therefor, the internal energy of the engine is 1571 joules

Answer 2

Answer:

The change in internal energy of the engine is -1,571 Joules.

Explanation:

Change in internal energy (∆U) = energy output (U2) - energy generated (U1)

U1 is the energy generated = 2203 Joules

U2 is the energy output = 632 Joules

Change in internal energy (∆U) = 632 - 2203 = -1,571 Joules