Can someone help me with this with work shown thank you!

1 ) If you are floating on your back with lungs ! In vo yang full of air , then exhale releasing all the air you sink, why is that? Consider volume, mass and density as it relates to buoyancy , ? " ) to 8 The noise coming from is car's in a parking lot waves was found to be 89 dB when idling . After 8 of the cars leave , what is the remaining deabel level ? " long fol mol of Neon gas is kept in a 12 Li container at 3 atm of pressure, Find the average kinetic energy of Neon of mass 2.04 x10:26 ka . Thermo K/ A specific car engine operates between a high temp of 150 . Fi and a low temp of 5. F . what is this engines maximum efficiency ? ?In