haruspex's latest activity

Thinking about it some more, I have decided it is not helpful to describe it the way I did, with the ##\lambda v^2## being subtracted...

Now I'm confused… you previously mentioned "indagate", an archaic but valid word meaning to investigate, from the Latin "indagare"...

The retardation force on the horizontal portion is not the only reason the tension reduces. Consider a massless string but with a mass...

Think about the connection between those observations.

It is stated as frictionless, but it makes no difference anyway.

Sure, but that’s just two plates. What if, e.g., we start with two positively charged plates then add a grounded plate, not between...

The tension is at different angles in different places. Where will its y component be mg? No, the tension will keep changing. Often...

First, think about the equilibrium position. Can you draw that? Clearly the centre mass will keep descending as long as it is above...

It is the model everyone uses, e.g...

The effect of a force F on a mass m in time ##dt## is to accelerate it by ##dv=F\cdot dt/m##. If instead the force is ##F-dF## then the...

This is what I am missing. How does that follow?

But I don’t see a valid argument for that in the concentric sphere model. A single infinite charged plate clearly exerts a field on...