Question

A heat engine undergoes a process in which its internal energy decreases by 400.0 J while it is doing 250 J of work. What is the net heat that is taken in (or given out) by the engine during this process.

Answer 1

Answer-

Net heat taken out is 150J

Step By Step Explanation-

In context to the given question:-
we have to find Net heat given out by the engine

We know that,

Work done = 250J
Decrease In internal energy = 400J
Heat given out = ?

Now we know,
The internal energy of a system will decrease only when the system is doing work and/or gives some heat out.

By This we can say that,

Decrease in Internal Energy = Work-done + Heat Given out

Let the Heat given out be (Q)

By putting the values
We get,

400 = 250 + Q

By transposing
We get,

Q= 400-250
Q = 150J

Therefore, Net heat taken out is 150J