- #1
gills
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My professor brought this up in class the other day, but has yet to elaborate on it and i can't stop thinking about it. I don't know if my wording is correct either so correct me if I'm wrong:
The magnetic force will always act perpendicular to the displacement of a particle. Therefore, the magnetic force never actually does any work because the angle between this force and the displacement of a particle is 90 degress and the cos(90)=0.
If this is the case, why is that in a junkyard the large cranes with magnets that can pick up a car can do the work of lifting a junk car to a height where it gains energy - mgh? Surely the magnetic force is involved in this somehow, but if it doesn't do the work, what does?
Obviously there are other things going on, but if someone can enlighten me, that'd be great.
Thanks
The magnetic force will always act perpendicular to the displacement of a particle. Therefore, the magnetic force never actually does any work because the angle between this force and the displacement of a particle is 90 degress and the cos(90)=0.
If this is the case, why is that in a junkyard the large cranes with magnets that can pick up a car can do the work of lifting a junk car to a height where it gains energy - mgh? Surely the magnetic force is involved in this somehow, but if it doesn't do the work, what does?
Obviously there are other things going on, but if someone can enlighten me, that'd be great.
Thanks