Centripetal Force

[vampireheart11]

Hi!

Can anyone explain the involvement of centripetal force in the operation of a washing machine? And how the spin dryer of the machine is able to dry the clothes?

[swansont]

Hi!

Can anyone explain the involvement of centripetal force in the operation of a washing machine? And how the spin dryer of the machine is able to dry the clothes?

 

What do you think?

 

Is this a homework question?

[CaptainPanic]

You can actually test this at home. It's a fun experiment, and it will make a lot of things wet around you:

 

-Take a towel, and soak it in water.

-Swing it rapidly around, and see if the towel is losing water or not.

-If other things get wet, then it is probably safe to conclude that this water is coming from the towel. (Don't do this in the rain, you cannot observe the water!)

-If other things got wet, you can conclude that the towel became a little drier.

[timetes]

i get it but then whats the purpose of the heat

[swansont]

i get it but then whats the purpose of the heat

 

Water evaporates faster as temperature goes up.

[npts2020]

It is the heat that dries the clothes, not the centripital force. The reason a drier rotates is for the same reason you hang clothes on a line instead of just leaving them in a pile to dry.

[swansont]

It is the heat that dries the clothes, not the centripital force. The reason a drier rotates is for the same reason you hang clothes on a line instead of just leaving them in a pile to dry.

 

The centripetal force does do some drying in the washing machine, during the spin cycle.

[npts2020]

The centripetal force does do some drying in the washing machine, during the spin cycle.

 

Very true in the washer. Similar to swinging a wet towel around your head. It would be a mistake to think that has more than a negligible amount, if anything, to do with the drying in a dryer, though.

[dirtyamerica]

The centripetal force that acts on the laundry is done by the spinning drum. It keeps the clothing from flying off. At the top of the path of the clothing's travel, additional centripetal force (gravity) kicks in and the clothing falls until it meets back up with the dryer drum (having overcome the centrifical force of it's acceleration (not really and change in speed but it's constantly changing direction). The falling clothing allows the laundry "air time" to aid in drying and a mechanical way of changing the position of the fabrics so different areas are exposed to the warm air.

[swansont]

Very true in the washer. Similar to swinging a wet towel around your head. It would be a mistake to think that has more than a negligible amount, if anything, to do with the drying in a dryer, though.

 

Quite right. The tumbling is to expose surfaces to allow water to evaporate.

[npts2020]

Exactly. Kinda like hanging them instead of leaving them in a pile, then blowing hot air over them.

[north]

Hi!

Can anyone explain the involvement of centripetal force in the operation of a washing machine? And how the spin dryer of the machine is able to dry the clothes?

 

the washing machine ;

 

pins clothes to the wall of the washing machine drum and draws out the water by shear rotational speed

 

dryer ;

 

heat and by rotation by the dryer drum exposes all clothes to heat and also expending moisture into the outside

 

oops

 

neither the washing machine or dryer have anything to do with centripetal force

 

centripetal force ;

 

directed or tending towards the center

 

the opposite of centrifugal

[swansont]

the washing machine ;

 

pins clothes to the wall of the washing machine drum and draws out the water by shear rotational speed

 

dryer ;

 

heat and by rotation by the dryer drum exposes all clothes to heat and also expending moisture into the outside

 

oops

 

neither the washing machine or dryer have anything to do with centripetal force

 

centripetal force ;

 

directed or tending towards the center

 

the opposite of centrifugal

 

 

No, that's incorrect. The force that the washer exerts on the clothes in the spin cycle is toward the center of the machine. Which is exactly what the centripetal force is.

[Severian]

It would be a mistake to think that has more than a negligible amount, if anything, to do with the drying in a dryer, though.

 

I very much doubt that. In fact, I have seen a faulty dryer which had a broken heating element (or whatever it is that provides heat) but could still spin the clothes. Although it didn't get them completely dry, they were no longer wet after the cycle - only damp.

 

Sometimes you get these spinner things in pool changing rooms too. Put your swimsuit in for 5 seconds and it gets spun with no heat. It comes out damp, but is a lot dryer than you could achieve by wringing out.

[npts2020]

I very much doubt that. In fact, I have seen a faulty dryer which had a broken heating element (or whatever it is that provides heat) but could still spin the clothes. Although it didn't get them completely dry, they were no longer wet after the cycle - only damp.

 

Sometimes you get these spinner things in pool changing rooms too. Put your swimsuit in for 5 seconds and it gets spun with no heat. It comes out damp, but is a lot dryer than you could achieve by wringing out.

 

Clothes will also dry in freezing cold air when hung out on a line so the fact that the heating element doesn't work only decreases the efficiency and doesn't prevent the machine from totally working. I am not familiar with spinners in a pool locker room but I would be willing to bet that their rotation speed is much higher than a dryer, similar to a washing machine's spin cycle. The high speed will fling the water out of the fabric. In a dryer the idea is just to keep exposing surfaces to hot air for efficiency sake (reason for the slower speed). Assuming they are already wrung out from the spin cycle of the washer, somebody would have to show me that a dryer spins fast enough to be above the minimum speed required for a measurable amount of water to do anything besides evaporate from the clothes.

[Severian]

I am not familiar with spinners in a pool locker room but I would be willing to bet that their rotation speed is much higher than a dryer, similar to a washing machine's spin cycle.

 

Maybe that is the crux. In my part of the world we usually don't have separate dryers - we have washer-dryers which do both jobs, and the dryer part spins (at times) as fast as the spin cycle.

[npts2020]

Maybe that is the crux. In my part of the world we usually don't have separate dryers - we have washer-dryers which do both jobs, and the dryer part spins (at times) as fast as the spin cycle.

 

Yes, I can now see why you had questions about what I said.