Which structures protect the cell? check all that apply.

- cell wall
- cell membrane
- mitochondrion
- nucleus
- ribosome
- golgi body

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.