A submerged ball pretty simple but im just learning this

[biggy135]

1. A ball of mass mass b and volume V is lowered on a string into a fluid of density Pf. Assume that the object would sink to the bottom if it were not supported by the string. What is the tension in the string when the ball is fully submerged but not touching the bottom. Solve using equation only.

So g is gravity. V is Volume. Pf is density. Mass is Mb.


2. So i know that pressure = force/area which probably is revelvant. The question only asks for the equations.



3. I would think that it would be this: (Pf * g * Mb) / V ...

 

[biggy135]

mass * acceleration = tension...

 

[biggy135]

So:

Hint 2. Find the magnitude of the buoyant force

Find , the magnitude of the buoyant force.

Which i found to be: V * Pf * g

and i know mass * acceleration = tension but i don't know how to combine all these terms in order to get a correct answer.

 

[biggy135]

When i try this:

(Mb * g) - (V * Pf)

I get "The buoyancy term in your answer has dimensions of mass, not force."

 

[biggy135]

Nevermind. I solved it...

(Mb * g) - (V * Pf * g)

stupid mee haha