Why can energy move through outer space by radiation, but not by convection or conduction

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer