cancel
Showing results for
Did you mean:
cancel
Showing results for
Did you mean:

Community Tip - You can Bookmark boards, posts or articles that you'd like to access again easily! X

14-Alexandrite

## Density and an Immersed Block

So today's challenge...

So I have a problem to which I am given the answer. The real issue is that I need to understand how the answer is derived.

I have attached a word document which gives the problem and the solution. I understand the first steps taken in that the resultant forces have to be at equilibrium as the block immersed (and floating) in the 2 liquids is at rest.

i.e

Then by factoring g and A out of the RHS and dividing both sides by gA I am left with:

Then as the question calls for the ratio h1/h2, I believe that I multiply out the LHS then divide both terms on both sides by h2 to get:

I know that the example in the question factors the LHS but I don't believe this is necessary. The problem I am then having is that the question's given answer in the attached document seems to suggest the ultimate answer is:

however, from everything I have tried algebraically by hand, the likes of Cymath / wolfgram Alpha and Mathcad itself the answer is suggested to be:

Am I going mad somewhere or am I going to need to be brave enough to question the professor who issued the model answer?

Thanks to anyone that can put me out of my misery!

Andy

1 ACCEPTED SOLUTION

Accepted Solutions
23-Emerald III
(To:awibroe)

You probably missed the minus-sign just before the ratio.

That makes the rho and rho2 swap places if you bring it in.

Luc

4 REPLIES 4
14-Alexandrite
(To:awibroe)

The attachment didn't seem to work. This is the question/ answer:

23-Emerald III
(To:awibroe)

You probably missed the minus-sign just before the ratio.

That makes the rho and rho2 swap places if you bring it in.

Luc

14-Alexandrite
(To:LucMeekes)

‌A bit embarrassing but yes that was my omission...

cheers!

21-Topaz II
(To:awibroe)

A bit of hydrostatic?

I apologize for some mistakes and for  a not perfect translation.

Announcements