Centrifuges

The FG force pointing downwards is the force of gravity emitted on the object by the Earth, also known as the weight.

The FA force, or applied force, is at a slant because the test tube is placed at an angle when inside the centrifuge, as demonstrated in the first picture.

FAY and FAX are the vector components of FA, with theta being the angle to the horizontal.

3. It is also used when testing an astronauts physiological reaction during their training.

FBD

Definition

Should it really be called a centrifuge?

Science dictionary:

An apparatus that separates objects of different densities via circular motion.

1. They are called centrifuges because they supposedly perform their task with the use of a "Centrifugal Force," which does not exist

A machine that rotates samples at high frequencies, which causes objects to be displaced outwards, usually as a byproduct of inertial resistance.

2. They actually make use of a centripetal force, using a centrifugal sensation as a technique for separating substances

3. They manipulate the centripetal force and acceleration, using it in order to keep some things moving in a circular path while others try to break free of it, pushing themselves to the side.

How it works?

Procedure:

1. Test tubes are placed in the centrifuge

2. The centrifuge begins to rotate at high frequencies(rpm)

A loaded centrifuge

Since the objects inside the test tube have different densities, they separate during the rotations

Objects of less mass need less of a centripetal force to stay in circular motion

1. The denser ones sink to the bottom

2. The ones of less mass rise to the top

This allows them to rise to the top of the tube, since it is closer to the center

3. This manipulates the force of gravity and the angle at which the test tube is placed, which is broken up into x and y vectors.

Denser objects need more of a centripetal force to rise to the top

1. This is not achieved, and is not supposed to be achieved

2. They then stay at the bottom of the tube due to their inertia and centrifugal sensation

This idea of "layering" by mass helps separate and identify substances and take accurate ratios of their relative quantities

an example of separated liquids, in layered form

2. Another example would be separating milk and cream.

1. Primarily used for separating bodily liquids such as red blood cells from white blood cells from plasma.

In this video, a centrifuge is used to filter and refine oil by separating it from the clumps and undesireable portions that are more dense than the pure oil itself.

Watch an Oil Centrifuge in Action

Uses

Centrifugal simulation

Separated blood

7. Video: http://youtube.com

6. Plasma scheme: http://upload.wikimedia.org/wikipedia/commons/1/11/Blood-centrifugation-scheme.png

5. Astronaut centrifuge: http://www.scotto.net.au/Moscow%20leg%20106.jpg

4. Centrifuge with hand: http://biology.clc.uc.edu/fankhauser/Labs/Genetics/DNA_Isolation/DNA_Isolation_jpg/05_centrifuge_P2060005.jpg

3. Blood sample: http://www.nsbri.org/HumanPhysSpace/focus3/fig2.jpg

2. Centrifuge: http://www.ktf-split.hr/glossary/image/centrifuge.gif

1. Definition: http://dictionary.reference.com/browse/centrifuge

Attributions