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How Do I Do This Problem?i Only Have A Day Left Please Help


Qwertyasd

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How much work has to be done to just fully immerse a cube of density 500kg/m^3, a side length of 30 cm into a container of water having a base area of 45 cm *60 cm, a density of 1000kg/m^3, and acceleration due to gravity of 10 m/sec^2?

I'm not doing your homework for you but am prepared to help.

 

What ideas do you have for how to set about this? One clue would be: what level do you think the cube will naturally float at?

 

And another would be: what happens when you depress it so that it is just immersed?

 

What do you think? 

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I used the work energy theorem.

∆K=W(gb)+W(gv)+W(B)+W(F)

Where

W(gb)-is the decrease in gravitational potential energy.

W(gv)-the increase in gravitational potential energy of the water in the vessel.(when the block is immersed the water level risises i think)

W(B)-the work done on the block by Bouyant force.

W(F)-work done by the external force to just immerse the block.

∆K-the change in kinetic energy (0 as it is given that the process is happens slowly).

My doubts are:-

1.even if I find how much water level raises how will I know how much the centre of mass will raise?

2.are the work done by Bouyant force and the water body's realated or do they want h other in any way?

I just need help in the method to solve and the cube will be initially half immersed in water.

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