I just did a quick read on it on it. “Work” is the application of force over time in the direction the object is moving. Pushing a shopping cart for example is work, because you have to constantly apply force to it.
From what I’ve read, it seems that magnetic force doesn’t do work because it doesn’t apply force in the direction the object moves. Magnetic force only “deflects” or changes the direction of an object with an existing velocity. It’s only a deflection because the force applied is always perpendicular to the direction of the velocity.
To use the previous shopping cart example, picture a shopping cart that already has a forward velocity that passes a magnet. The magnet only applies a force to the side of the cart towards the magnet. This doesn’t push the cart itself, but changes the direction of its velocity towards the magnet.
But that’s true of gravitational forces too, otherwise satellites wouldn’t have constant speed. It’s silly and misleading to say that magnetic forces do no work. If I turn an electromagnet on next to a spoon, the spoon will move and the magnetic force did some work.
IIRC it depends on the frame of reference. Relative to a magnetic field, the only thing a magnetic force does is changing the velocity direction of affected objects. All work regarding the absolute magnitude of the velocity is zero (no lateral acceleration).
Tried to read about this but it all goes over my head. If anyone wants to ELI5 why magnetic forces do no work, that would be great :)
I just did a quick read on it on it. “Work” is the application of force over time in the direction the object is moving. Pushing a shopping cart for example is work, because you have to constantly apply force to it.
From what I’ve read, it seems that magnetic force doesn’t do work because it doesn’t apply force in the direction the object moves. Magnetic force only “deflects” or changes the direction of an object with an existing velocity. It’s only a deflection because the force applied is always perpendicular to the direction of the velocity.
To use the previous shopping cart example, picture a shopping cart that already has a forward velocity that passes a magnet. The magnet only applies a force to the side of the cart towards the magnet. This doesn’t push the cart itself, but changes the direction of its velocity towards the magnet.
But that’s true of gravitational forces too, otherwise satellites wouldn’t have constant speed. It’s silly and misleading to say that magnetic forces do no work. If I turn an electromagnet on next to a spoon, the spoon will move and the magnetic force did some work.
IIRC it depends on the frame of reference. Relative to a magnetic field, the only thing a magnetic force does is changing the velocity direction of affected objects. All work regarding the absolute magnitude of the velocity is zero (no lateral acceleration).
How fucking smart do you think 5 year olds are?
When you hold two strong magnets an inch apart, then let them go it looks like they move themselves (add velocity)?
What makes the magnets start moving towards each other from a complete stop?