Magnetism and kinetic force

[Daymare17]

If you repel something with an electromagnet, is the electromagnet pushed with an equal force in the opposite direction from what it pushes?

 

For instance: In the core of a fusion reactor, plasma is confined by a magnetic field that basically equals the pressure inside the core of the sun. Does this mean there is a huge pressure outwards, on the walls that the magnets are mounted on? How big is this pressure?

[Kedas]

first question: Yes.

second: Yes, it should, how much? I don't know.

Are you planning to build a fusion reactor?

[swansont]

Same force, yes, but not the same pressure. Pressure varies with area, so the pressure gets larger as the area gets smaller. It's why hydraulic lifts can work.

 

So if the outside area is a meter in scale, and the fusion area is a mm in scale, the pressure goes up by a factor of a million.

[J.C.MacSwell]

Same force' date=' yes, but not the same pressure. Pressure varies with area, so the pressure gets larger as the area gets smaller. It's why hydraulic lifts can work.

 

So if the outside area is a meter in scale, and the fusion area is a mm in scale, the pressure goes up by a factor of a million.[/quote']

 

Are you sure that's not vice versa?

 

Edit:nevermind, I think I took it out of context. I keyed in on the hydraulics lift part.

[swansont]

Are you sure that's not vice versa?

 

Edit:nevermind' date=' I think I took it out of context. I keyed in on the hydraulics lift part.[/quote']

 

No, you're right. I shifted gears a little. The concept is similar - pressure vs. force - but the application is different.

[Kedas]

I was curious myself so:

...However, the density of the plasma, n, can be relatively low at about 10^-20 m³. The resulting pressure in the plasma is therefore only about one atmosphere.

found the answer on this page:http://physicsweb.org/articles/world/17/1/6

 

Also interesting to know we are talking of magnetic fields of 1T to 5T.

[Primarygun]

Same force, yes, but not the same pressure. Pressure varies with area, so the pressure gets larger as the area gets smaller. It's why hydraulic lifts can work.

This accounts for why small experiments playing with the solenoid always allow a magnet passes through itself?

[Kedas]

What do you mean?

 

BTW pressure=force/area, ignore that 'hydraulic lifts' sentence.

hydraulic lift: a small force is put on a small area so the force would be bigger at the other end were there is a big area. (pressure is the same for both area's)