- #1

- 169

- 4

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter abdo799
- Start date

- #1

- 169

- 4

- #2

- 1,254

- 106

Your comment about a trapezium implies that there would be no water pressure on the angled sides? Of course that is not the case.

- #3

SteamKing

Staff Emeritus

Science Advisor

Homework Helper

- 12,798

- 1,670

Any floating body can be overloaded, even the rectangular one.

- #4

- 169

- 4

Your comment about a trapezium implies that there would be no water pressure on the angled sides? Of course that is not the case.

Correct me if i am wrong ( i am new to the world of physics) , but regarding the angled sides, doesn't pascal's second law apply here? if it does the force should be perpendicular to the surface , no upwards. If it doesn't apply , can you tell me please to calculate the water pressure on those angled sides ? PS: i am not arguing if the thing will float or sink, i know it will float , just trying to know why , thanks

- #5

Chestermiller

Mentor

- 21,948

- 4,996

- #6

- 15,415

- 687

Mathematically, ##\vec F = - \oint_S P(S)\,\hat n(S)\,dS##, where ##P(S)## is the pressure at some point on the surface and ##\hat n(S)## is the unit outward normal to the surface at that point. This is a mess in general. However, the divergence theorem tells us how to rewrite this surface integral as a volume integral. This volume integral is much more tractable than is the surface integral and it is this volume integral that leads to Archimedes' principle.

- #7

Chestermiller

Mentor

- 21,948

- 4,996

Yes. I had this approach in mind. In my response, I just wanted to explain how the pressure on the slanted sides of the body comes into play. This is a point of confusion for many new initiates.Mathematically, ##\vec F = - \oint_S P(S)\,\hat n(S)\,dS##, where ##P(S)## is the pressure at some point on the surface and ##\hat n(S)## is the unit outward normal to the surface at that point. This is a mess in general. However, the divergence theorem tells us how to rewrite this surface integral as a volume integral. This volume integral is much more tractable than is the surface integral and it is this volume integral that leads to Archimedes' principle.

Chet

- #8

SteamKing

Staff Emeritus

Science Advisor

Homework Helper

- 12,798

- 1,670

It's wider at the top than the bottom.

- #9

- 169

- 4

Thanks guys , you really helped me

Share: