The first and second laws of thermodynamics
Answers are for parents and teachers.
1
A gas is given 1500 J of heat and does 600 J of work. What is ΔU (J)?
900
2
300 J of work is done on a gas (A = –300 J) and the internal energy rises by 250 J. What is Q (J)? (Q = ΔU + A)
-50
3
In an isobaric process p = 150 kPa (150000 Pa), ΔV = 0.004 m³. What is the work (J)?
600
4
Why is the oscillation of a pendulum with friction irreversible?
Part of the mechanical energy turns into heat spread to the surroundings and does not return by itself.
5
State Planck’s formulation in your own words.
No cyclic process can turn heat completely into work.