Buoyant force acting on an inverted glass in water

[erobz]

I appreciate your help. I didn't use P_atmL/(L -δ) = P_atm+ρg(h-δ) because
2nd degree equation was obtained ...

I have used the formula you suggested ...

What formula?

 

[MatinSAR]

Think about what h=0 physically corresponds to.

Thank you for you rhelp and time.

What formula?

This post :
https://www.physicsforums.com/threa...-inverted-glass-in-water.1047903/post-6831524

 

[erobz]

Thank you for you rhelp and time.

This post :
https://www.physicsforums.com/threa...-inverted-glass-in-water.1047903/post-6831524

I don't understand! I solved it as a quadratic. However, your result indicates that my quadratic must be factorable I believe?

 

[MatinSAR]

I don't understand! I solved it as a quadratic. However, your result indicates that my quadratic must be factorable I believe?

Maybe I made a mistake ...
was my answer correct ??

 

[erobz]

Maybe I made a mistake ...
was my answer correct ??

It plots identically to my solution?

 

[MatinSAR]

It plots identically to my solution?

Let me send you a picture of what I have done ...

 

[MatinSAR]

It plots identically to my solution?

My mistake is here :

So to find delta we have to solve a quadratic equation ...

The question only asked about the increase and decrease of F force, I didn't want to waste your time at all... I'm sorry...



edit :

I have solved that quadratic equation ...

 

[erobz]

My mistake is here :
View attachment 318768

So to find delta we have to solve a quadratic equation ...

The question only asked about the increase and decrease of F force, I didn't want to waste your time at all... I'm sorry...



edit :

View attachment 318770

I have solved that quadratic equation ...

What you did on accident the first time by omitting $\delta$ was actually a really good approximation for $\delta \ll h$. For the parameters I used I couldn’t tell the apart.

 

[erobz]

My mistake is here :
View attachment 318768

So to find delta we have to solve a quadratic equation ...

The question only asked about the increase and decrease of F force, I didn't want to waste your time at all... I'm sorry...



edit :

View attachment 318770

I have solved that quadratic equation ...

I wanted you to explore it. It wasn’t a waste of my time at all!

 

[MatinSAR]

I wanted you to explore it. It wasn’t a waste of my time at all!

Thank you for your help and time ... 🙏🙏