# Homework Help: Metal object and Charge

1. Oct 6, 2011

### cheerspens

1. The problem statement, all variables and given/known data
The picture for my question is attached. I labeled on the picture, which is a metal object, where I thought the distribution of charges on the surface would be if it has a net negative charge and the electric field lines near the surface.
• At what point on this object would be most likely to receive a chock if you brought your hand near?
• Which point, A or B, on theis object's surface will be at the highest potential?

2. Relevant equations
No equations for this.

3. The attempt at a solution
For the first question, I want to say the answer would be in the region where the negative charges (electrons) are located. Is this correct?
For the second question, I'm confused because I want to say that the potentials would be equal.

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2. Oct 7, 2011

### Staff: Mentor

On a charged conductor charges tend to get concentrated at pointy bits. The field strength spikes at, well, spikes! This is why high voltage systems (like Tesla coils and Van de Graff generator accumulators) tend to be smooth surfaced and often spherical, to minimize the radius of curvature of the components.

To understand why this might be, consider the mutual forces that act between like charges residing on the surface of a conductor. What's the general direction of those force vectors on a smooth (flat) surface? How about on a pointy needle?