# How to find potential difference between 2 parallel deflection plates

1. Apr 28, 2013

### firezap

1. The problem statement, all variables and given/known data
Describe by pointform how to find potential difference between parallel deflection plates, ΔV₂ = ?
You don't have to solve.

ΔV1 = 1.38 kV
Δx = 5 cm
Δy = 0.49 cm
r = 5.2 cm
q = 1.6 x 10^-19 C
m = 9.11 x 10^-31 kg
k = 9 x 10^9 Nm^2/C^2

2. Relevant equations
ε = ΔV/d
W = ΔEe = qΔV
V = kq/r
Fe = kq1q₂/r^2
Fe = qε
Ee = kq1q₂/r

3. The attempt at a solution
i don't have the velocity so i don't know how. If i did have velocity i would find time.

#### Attached Files:

File size:
56.6 KB
Views:
85
• ###### lab crt.jpg
File size:
43.4 KB
Views:
75
Last edited: Apr 28, 2013
2. Apr 28, 2013

### mrcotton

I am on thin ice here, but its ok I am happy making a fool out of myself

Don't you use the potential between the cathode and the anode and the charge on the electron to calculate the energy gained in traversing the first part of your diagram and equate this to the kinetic energy to solve for the velocity as you leave the slit in the vertical anode

1/2 mv^2=eV

Last edited: Apr 28, 2013
3. Apr 28, 2013

### firezap

Ty what do I do after?

4. Apr 30, 2013

### firezap

i have the initial velocity what do i solve for next? ε, acceleration, Fe, final velocity??? how to find potential difference

Last edited: Apr 30, 2013
5. May 2, 2013

### firezap

never mind i got it.