Question

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j?

1. write the equation

2.list out your known variables

3.plug the numbers into the equations

4.Solve

5.write your solution statement that includes initial energy and final energy added

Answer 1

2500 J

Explanation:

As we know that from first law of thermodynamics we have

`Q = W + \Delta U`

here we know that

Q = heat given to the system

W = work done by the system

`\Delta U` = change in internal energy of the system

now we will have

Q = 1000 J

`U_i = 2000 J`

Work done by the piston = 500 J

so work done by system of gas = (work done by piston)

now from above equation we have

`1000 = \Delta U + 500`

`\Delta U = 500 J`

now we know that

`\Delta U = U_f - U_i`

`500 = U_f - 2000`

`U_f = 2500 J`

So final internal energy of the gas is 2500 J while initial internal energy is given as 2000 J