Which has more volume a kilogram of feathers or a kilogram of bricks answer quickly you what is the relationship between density and buoyancy of a fluid explain many fish can adjust the density of their bodies by controlling the amount of gas in a sack called a swim blatter how what do you amount of gas in swimbladder have to change in order for the fish to swim deeper underwater explain your answer you guys me with these questions it is due tomorrow and i really need

I'll answer the first question: the answer isa kilogram of bricks.

1 kilogram of feathers has more volume than 1 kilogram of brick. feathers have less density than brick therefore they take up more space in a container.
density & buoyancy
when you place an object in a liquid such as water and it floats, it is said to have buoyancy.
the more density an object has, the less buoyancy it has, and it will sink.
swim bladder
a fish controls its depth by adding or subtracting gas from its swim bladder. by squeezing the bladder and releasing gas the fish becomes more dense and therefore it sinks deaper. if the fish adds gas to the bladder it becomes less dence, increasing its buoyancy and it will rise up in the water.