What is the correct answer to the electric strength problem?

  • Thread starter Thread starter NINHARDCOREFAN
  • Start date Start date
  • Tags Tags
    Electric Strength
AI Thread Summary
The discussion centers on solving an electric strength problem related to a parallel-plate capacitor. The user initially calculated the charge using the formula q = E * ε * A but found their answer incorrect when compared to the expected unit of 1e-6c. They later realized that using a different formula, q = E * k * ε * A, provided the correct answer. The problem involves a capacitor with specific dimensions and a dielectric constant for paper. Ultimately, the user resolved their confusion and confirmed the correct approach to find the maximum charge.
NINHARDCOREFAN
Messages
118
Reaction score
0
https://hw.utexas.edu/tmp/Muddam1/1077653690Xuj.pdf

I did this: I manipulated E = \frac{q}{\epsilon*A} to get q = E*\epsilon*A (E= electric strength), so 1.6e7*8.85e-12*.0246*.0501 = 1.74516e-7 but because the HW asks the answer to the 1e-6, I divided 1.74516e-7/1e-6= .174516 but it's wrong does anyone know why?
 
Last edited by a moderator:
Physics news on Phys.org
Your link does not work.
 
Whoa...

Ok this is the problem

009 (part 1 of 2) 10 points
A parallel-plate capacitor of dimensions
2:46 cm £ 5:01 cm is separated by a 0:61 mm
thickness of paper.
Find the capacitance of this device. The
dielectric constant · for paper is 3.7. Answer
in units of pF.

I got this right.

010 (part 2 of 2) 10 points
What is the maximum charge that can be
placed on the capacitor? The electric strength
of paper is 1:6 £ 107 V=m. Answer in units of 1e-6c.
this is the one I need help on
 
...

Never mind, I got it.
 
So what's the answer?
 
I used a different formula to get the answer: q = E*k\epsilon*A
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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