Time period of oscillation of charge in front of infinite charged plane

AI Thread Summary
The discussion focuses on calculating the time period of oscillation for a charged particle near an infinite charged plane. The initial calculation for the time to reach the plane is expressed as t = root(4εmd/σq). It is debated whether the oscillation period is double this time, with a consensus emerging that it should actually be four times t. The final agreement confirms that the correct time period of oscillation is 4t. The conversation highlights the importance of careful analysis in deriving physical equations.
Saptarshi Sarkar
Messages
98
Reaction score
13
Homework Statement
A negetive point charge -q with mass m is held at rest at a distance d from an infinite charged plane with charge density σ and released. Find time period of oscillation (assuming that charge can freely move through plane without disturbing the charge density).
Relevant Equations
F = -qσ/2ε
a = -σq/2εm
I tried to calculate the time the charged particle will take to reach the plane using the a and using d=1/2at² and found the t to be equal to root(4εmd/σq).

I guess the time period of oscillation will be double of t (by symmetry), i.e. 2root(4εmd/σq). I don't know if this is correct.
 
Physics news on Phys.org
I should have looked at your work more closely. You have the picture quite correct.
Only small thing - if t is the time to fall to the plane, is the period really 2t?
 
  • Like
Likes Saptarshi Sarkar
rude man said:
I should have looked at your work more closely. You have the picture quite correct.
Only small thing - if t is the time to fall to the plane, is the period really 2t?

Thanks, got it. It should be 4t.
 
Saptarshi Sarkar said:
Homework Statement:: A negetive point charge -q with mass m is held at rest at a distance d from an infinite charged plane with charge density σ and released. Find time period of oscillation (assuming that charge can freely move through plane without disturbing the charge density).
Homework Equations:: F = -qσ/2ε
OK
a = -σq/2εm

I tried to calculate the time the charged particle will take to reach the plane using the a and using d=1/2at² and found the t to be equal to root(4εmd/σq).

I guess the time period of oscillation will be double of t (by symmetry), i.e. 2root(4εmd/σq). I don't know if this is correct.
[/QUOTE]
Saptarshi Sarkar said:
Thanks, got it. It should be 4t.
Yes. Good going.
 
  • Like
Likes Saptarshi Sarkar
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