Question

A fisherman and his young son are in a boat on a small pond. Both are wearing life jackets. The son is holding a large helium filled balloon by a string. Consider each action below independently and indicate whether the level of the water in the pond, Rises, Falls, is Unchanged or Cannot tell.

Rises Falls Unchanged Cannot tell  The son finds a cup and bails some water out of the bottom of the boat?
Rises Falls Unchanged Cannot tell  The son pops the helium balloon?
Rises Falls Unchanged Cannot tell  The fisherman knocks the tackle box overboard and it sinks to the bottom?
Rises Falls Unchanged Cannot tell  The son gets in the water and pops the helium ballon?
Rises Falls Unchanged Cannot tell  The fisherman lowers himself in the water and floats on his back?
Rises Falls Unchanged Cannot tell  The fisherman lowers the anchor and it hangs one foot above the bottom of the pond?

Think about Archimedes Principle. How does the volume of fluid displaced by a body which `floats' differ from that for a body which sinks?

Answer 1

- the son finds a cup and bails done water-the total water and weight remains same hence level is​​​​​ uncahnged.

-the son pops the helium baloon- the downward weight increases and hence water level rises.

-when ta kle box is thrown, the displacement is the same hence the level remains unchanged.

-​​​​​​-the son gets into the water and pops the baloon-, the displacement increases and hence the level rises.

-the fisherman gets into the water-the displacement is same and level is unchanged.

- the fisherman drops the anchor - displacement same as before hence level is​​​​​ unchanged.