Question

submarine how to sink and float in water answer in two pages 500 words

musical instruments the scientific principles behind them ​answer in two pages 500 words

Answer 1

Here are some of their answers:

“Submarines use ballast tanks and compressed air. They have a vent at the bottom. To sink, valves at the top open and let water come in through the vent at the bottom and fill the ballast tanks. To float, they open the valves to let compressed air in to force the water out of the ballast tanks.” By Chris.

“A submarine works by having some tanks full of compressed air. If a submarine wants to go down it opens some air vents which allow the air to escape and then it fills up with water which sinks the submarine. But if a submarine wants to return to the surface all it has to do is release the stored compressed air which will push all the water out leaving the tank to have air in it which will cause the submarine to float to the surface.” By Harry.

“A submarine contains ballast tanks in its hull that use compressed air to change the density of the sub. By opening a valve, water fills the ballast tanks with water, thus increasing its density, thus making the submarine sink. If a submarine wants to float, compressed air gets pushed into the tanks, thus pushing the water out making it float.” By Matt.

“A submarine uses ballast tanks filled with compressed air and when needed the air is released and takes on water which increases the density making it sink but when the water is pushed out the sub’s density is decreased making it float.” By Jordan.