Which of the following would change a boat's center of gravity?

a. change the material it is made from

b. put a small cabin directly over the current center of gravity

c. add two small anchors on the outside middle of the boat, one on starboard (right), one on port (left)

d. lengthen the mast (the large pole that holds the sail), which is located on the back of the boat

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.