Question

Why does a block of plastic released under water come up to the surface of water?

Answer 1

A block of plastic released under water comes up to the surface of water because the buoyant force (upthrust ) acting on the block of plastic due to water is greater than its weight . The buoyant force is greater because the density of water is greater than the density of plastic.


Buoyant force:

Upward force acting on an object immersed in a liquid is called buoyant force .
The upward force exerted by a liquid is also known as upthrust.

As we lower an object into a liquid the greater upward pressure of liquid underneath it provides an upward force called the buoyant force or upthrust.

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Hope this will help you.....

Answer 2

Answer:

the density of plastic is less than water which result it in in a upward buyout force motors pushing the plastic block the surface of the water