Conceptual Question Regarding Fluids

[Deaddman]

Homework Statement

A friend and I were arguing about how tension created by a submerged ball affects the total weight of the container.

Homework Equations

I couldn't find anything similar to the situation, so I drew a quick picture to better illustrate the situation :D

A string is attached to the bottom of the beaker, and is stopping the plastic ball from floating to the top.

The Attempt at a Solution

The question was to find the total weight of the system. Clearly you need to add the weight of the water, the ball, and the beaker, but my friend says you also need to subtract the tension in the string, because it is pulling up on the beaker. I disagree. I argue that the tension pulling on the beaker is an internal force, so it does not affect the weight of the system at all.

Now, I can honestly see either him or me being right. I am unsure, which is what motivated me to post here, in hopes that someone could clear this up.

Thanks for any and all help.

 

[zhermes]

You are most certainly correct deaddman, for the same reason that you can't fly by lifting up on your boot straps...

 

[Deaddman]

Thanks very much for the quick reply, zhermes.

Cheers :)