Solving Buoyancy Problem: Ball Emerges from Water Surface

[Hitman6267]

Question
Suppose that you release a small ball from rest at a depth of 0.610 m below the surface in a pool of water. If the density of the ball is 0.290 that of water and if the drag force on the ball from the water is negligible, how high above the water surface will the ball shoot as it emerges from the water? (Neglect any transfer of energy to the splashing and waves produced by the emerging ball.)

My attempt
I tried mg = [tex]m_{f}[/tex] * g

but it didn't get me anywhere

Any ideas ?

 

[aim1732]

Why don't you apply Newton's second law on it? Then a little kinematics will help.

 

[Hitman6267]

It worked thank you :)

I tried it, but a mistake kept the density from cancelling out. I retried it after your suggestion and it worked.