Calculating Volume Charge Density: Simplified Earth Model

AI Thread Summary
To calculate the volume charge density in the Earth's atmosphere between altitudes of 260 m and 410 m, the electric fields measured at these altitudes are 148 N/C and 165 N/C, respectively. The problem suggests using Gauss's law, which relates electric flux to charge enclosed. By conceptualizing a box with the height difference between the altitudes and an area A, one can determine the total electric flux and subsequently the total charge inside the box. The uniformity assumption of charge density simplifies the calculations. This approach allows for the determination of the volume charge density in the specified region.
Jess155
Messages
1
Reaction score
0

Homework Statement


In a particular region of the Earth's atmosphere, the electric field above the Earth's surface has been measured to be 148 N/C downward at an altitude of 260 m and 165 N/C downward at an altitude of 410 m. Calculate the volume charge density of the atmosphere, assuming it to be uniform between 260 and 410 m. (Hint: You may neglect the curvature of the earth. Why?)

Homework Equations


volume charge density = Q/V

The Attempt at a Solution


No clue where to even start. And why they gave me two altitudes and E fields
 
Physics news on Phys.org
You can imagine a box shaped structure whose height is that of the difference between the given altitudes and the upper and lower surfaces have area A. Then calculate the total electric flux through the box. Assume a charge density $$\rho$$ and calculate total charge inside the box. Then finally, use Gauss's law.
 
Jess155 said:

Homework Statement


In a particular region of the Earth's atmosphere, the electric field above the Earth's surface has been measured to be 148 N/C downward at an altitude of 260 m and 165 N/C downward at an altitude of 410 m. Calculate the volume charge density of the atmosphere, assuming it to be uniform between 260 and 410 m. (Hint: You may neglect the curvature of the earth. Why?)

Homework Equations


volume charge density = Q/V

The Attempt at a Solution


No clue where to even start. And why they gave me two altitudes and E fields
Hello Jess155. Welcome to PF !

You titled the thread, "Gauss's law?" .

That's a good place to start.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top