Finding Equilibrium Angle in Uniform Electric Field

AI Thread Summary
To find the maximum angle of deviation for a tiny conducting ball in a uniform electric field, the equilibrium conditions require that the sum of forces in both the x and y directions equals zero. The force due to the electric field is calculated as F_field = qE, where q is the charge and E is the electric field strength. By substituting this into the equilibrium equations, the relationship tan(θ) = qE/(mg) is derived. This formula allows for the calculation of the angle θ based on the given parameters of mass, charge, and electric field strength. The discussion concludes with the user successfully solving the problem with the provided guidance.
z_sharp
Messages
9
Reaction score
0
Hey all, I'm not sure where to start on this question. Any ideas would be spectacular.

A tiny conducting ball of mass 1.00 g and charge 20.0 times 10^{-6} is hung from a non-conducting, massless thread. The electric field of magnitude 10^3N/C existing in this region is uniform and horizontal. Find the maximum angle of deviation between the thread and the vertical for the equilibrium, position of the ball.

So far this is what I have
For equilibrium sum of all forces must equal 0
Therefor...
<br /> \begin{equation*}<br /> \begin{split}<br /> \ F_{{net}_x}=0 \\<br /> 0=F_{field}-{T_x} \\<br /> 0= ? - T\sin\theta<br /> \end{split}<br /> \end{equation*}<br />

<br /> \begin{equation*}<br /> \begin{split}<br /> \ F_{{net}_y}=0 \\<br /> 0=F_g-{T_y} \\<br /> 0=mg-T\cos\theta<br /> \end{split}<br /> \end{equation*}<br />

I'm not to sure what I do for the force of the electric field and how I encorperate that into the equation.

Thanks Everyone
 
Physics news on Phys.org
Your equilibrium conditions are OK:

F_{field}-Tsin \theta=0
mg - T cos \theta=0

Now you must take into account that F_{field}=qE (electric charge times electric field magnitude). You obtain then (by eliminating T):

tg \theta = \frac{qE}{mg}.
 
Thanks for your help, I was able to get the problem with the assistance you provided. :smile:
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top