- #1
Nick O
- 158
- 8
Homework Statement
Two identical beads each have a mass m and charge q. When placed in a hemispherical bowl of radius R with frictionless, nonconducting walls, the beads move, and at equilibrium, they are a distance d apart. a) Determine the charge q on each bead. b) Determine the charge required for d to become equal to 2R.
[See image]
https://www.physicsforums.com/attachments/61123
Homework Equations
Electric force [itex]\vec{F}_{e}=k_{e}\frac{q^{2}}{d^{2}}\hat{r}[/itex]
Gravitational force = [itex]-mg\hat{j}[/itex]
Normal force = [itex]\vec{n}[/itex]
[itex]|\vec{n}|cos(θ) = |\vec{F}_{e}|[/itex]
[itex]|\vec{n}|sin(θ) = mg[/itex]
... where θ is the angle between the normal force and the horizonal.
The Attempt at a Solution
The normal force equations above sum up my progress toward solving the problem. I believe that I somehow need to find the normal force in order to solve for the electric force, which I need in order to solve for q. But, to solve for the normal force, I need to solve for θ, and here I am stuck; I have two equations and three unknowns.
I feel that knowing the lengths of all three sides of the isosceles triangle formed by the center of the hemisphere and the two beads is significant, but I can't find any connection between the angles in that triangle and the angle of the normal force.
With that, I am at your mercy. Any guidance would be much appreciated.
4. Vaguely human introduction.
Hello! I am currently taking Physics II (a calculus-based course with a focus on electromagnetism), and am working toward BS in Computer Engineering. The problem above is, of course, homework. As such, I'm sure we can all agree that the most I should be given is a nudge in the right direction, and not the actual answer.
Thank you in advance.
5. Forum bug discovered.
Whenever I click "Preview Post", the post template is pasted at the end of the message box. To see what I mean, scroll down.
Homework Statement
Homework Equations
The Attempt at a Solution
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