S
strikerx
Guest
Two 7.38 cm diameter disks face each other, 2.34 mm apart. They are charged to ±4.86 nC. What is the electric field strength (in N/C) between the disks?
I'm having trouble with this question. I got the electric field to be about 62366 N/C for the positive charge and the negative of that for the negative charge. But both electric fields will point to the negative charge because positive ones point away while negative ones point toward. So is the answer just double one of the electric fields? And if so is it positive or negative? I used the formula for obtaining the electric field of a disk by getting the surface charge density (Q/(pi* R^2)) and then using this: (surface charge density/2*(8.85E-12))* (1/sqrt(1+(R/Z)^2)).
Z is about 0.00117 m since we need the halfway point between the two disks. R is the radius which is .0369 m. The surface charge density was 1.14E-6 C/m^2. Any help here would be appreciated.
Also, there is a second part to this question. A proton is shot from the negative disk towards the positive disk. What launch speed (in m/s) must the proton have to just barely reach the positive disk? I can probably figure this out myself though once I get the electric field but don't hesitate to offer advice.
I'm having trouble with this question. I got the electric field to be about 62366 N/C for the positive charge and the negative of that for the negative charge. But both electric fields will point to the negative charge because positive ones point away while negative ones point toward. So is the answer just double one of the electric fields? And if so is it positive or negative? I used the formula for obtaining the electric field of a disk by getting the surface charge density (Q/(pi* R^2)) and then using this: (surface charge density/2*(8.85E-12))* (1/sqrt(1+(R/Z)^2)).
Z is about 0.00117 m since we need the halfway point between the two disks. R is the radius which is .0369 m. The surface charge density was 1.14E-6 C/m^2. Any help here would be appreciated.
Also, there is a second part to this question. A proton is shot from the negative disk towards the positive disk. What launch speed (in m/s) must the proton have to just barely reach the positive disk? I can probably figure this out myself though once I get the electric field but don't hesitate to offer advice.