- #1

- 89

- 0

Am I totally wrong here?

- Thread starter Swatch
- Start date

- #1

- 89

- 0

Am I totally wrong here?

- #2

- 92

- 0

What?????????it is not moving

- #3

- 89

- 0

- #4

Doc Al

Mentor

- 44,975

- 1,245

An object spinning in a circle is most definitely accelerating! It is accelerating towards the center of the circle; this is usually called

- #5

- 89

- 0

That's what I thought. But wasn't sure because the object isn't in an inertial frame of reference.

- #6

MalleusScientiarum

- #7

- 89

- 0

An incompressible fluid with density rho is in a horizontal test tube of inner cross-sectional area A. The test tube spins in a horizontal circle with angular speed w. Gravitational forces are negligeble. An object of volume V and density RHOob has its center of mass at a distance Rcmob from the axis. Show that the net horizontal force on the object is rhoVw^2Rcm, where Rcm is the distance from the axis to the center of mass of the displaced fluid. I have already derived expressions for the pressure at a distance from the surface of the water, and for the pressure difference for a volume element of thickness dr. It seems to me that the net force on the object is the mass*acceleration of the displaced fluid volume.

I don't know how to treat this problem. I see the force as the mass*acceleration of the object + displaced water.

Could anyone please help me.

- #8

Doc Al

Mentor

- 44,975

- 1,245

The net force on any object is its mass time its acceleration. This object is being centripetally accelerated, so [itex]F_{net} = m a_c[/itex].Swatch said:It seems to me that the net force on the object is the mass*acceleration of the displaced fluid volume.

- Replies
- 5

- Views
- 2K

- Last Post

- Replies
- 7

- Views
- 4K

- Replies
- 10

- Views
- 3K

- Last Post

- Replies
- 9

- Views
- 2K

- Replies
- 1

- Views
- 1K

- Replies
- 1

- Views
- 3K

- Replies
- 2

- Views
- 2K

- Last Post

- Replies
- 6

- Views
- 759

- Last Post

- Replies
- 2

- Views
- 966

- Last Post

- Replies
- 1

- Views
- 740