I dont know if this is in the right area but i will ask anyway!! if it surposed to be in another area can you tell me. I was wondering how come the clothes in a washing machine when going thou the spin drying stage go around on the outside part and not around the bit in the middle? i got asked it today in physics. thanx for you help

Short answer, centripetal force pushes it out.

 

Long answer, the second derivative of the position vector for an object moving in a circle always yields an acceleration towards the center; and the force is felt opposite to direction of acceleration (when you brake in a car, you feel like you're being pushed forward even though you're slowing down).

fafalone said in post # :

Short answer, centripetal force pushes it out.

 

Wrong cause and effect. It's the tendency to keep moving in a straight line that causes it, the centripetal force is the reaction force from the outside that causes it to orbit the centre.

MrL_JaKiri,

 

I fail to see why fafalone was wrong and where your explanation is not exactly what he said, actually... :\

 

can you explain please?

I see it. Centripetal force isn't the same as inertia mooeypoo.

Yeah I know that. But I always thought that Centripetal force already included inertia in it... if you don't move something with "enough" inertia it won't really work..

 

I might be wrong here, that was my understanding though.

it works on the same principal as a centrifuge. or that trick when you spin a bucket of water around over you head and non comes out. btw, what`s the difference between centrifugal force and centripetal force?

That's what I was thinking.. isn't Centrifugal force already contain the inertia?? you can't have a centrifuce WITHOUT inertia... I was... always certain it just comes together :\

 

~moo

MrL_JaKiri said in post # :

 

Wrong cause and effect. It's the tendency to keep moving in a straight line that causes it, the centripetal force is the reaction force from the outside that causes it to orbit the centre.

 

Not quite.

I fail to see why fafalone was wrong and where your explanation is not exactly what he said' date=' actually... :\

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centripetal = "center seeking" A centripetal force can't push something away from the center.

 

As for the original question: in the middle of the washer, there is no force that would make the clothes go in a circle. That force is provided by the walls of the machine.

In a weightless enviroment the acceleration induced would glue the clothes to the drum. Because of gravity it falls at dryer speed across the center which is most efficient for drying. The only way to have the clothes stay in the center would be to have no gravity and no acceleration.

Just aman

In a weightless enviroment the acceleration induced would glue the clothes to the drum. Because of gravity it falls at dryer speed across the center which is most efficient for drying. The only way to have the clothes stay in the center would be to have no gravity and no acceleration.

Just aman

 

For a dryer. But the discussion is about washing machines, so the spin axis is perpendicular to the surface of the earth. Gravity is irrelevant to the discussion.

Only if it's a washer with a vertical drum.

 

My washer has a horizontal drum - use mine if you like.