Lab Simulation: Find the charge to mass ratio of an electron. 

Description
An electron moves  horizontally with speed 6.00 x 106 m/s between two neutral (uncharged) conducting plates. At t = 1.0 Ás, the plates become oppositely  charged, creating a uniform electric field in the region between them. (The time is displayed in units of Ás.) The electron deflects vertically upward or downward as it moves to the right a  distance x until it hits a detector. The magnitude and sign of the plate charges, and hence absolute value and direction of electric field, can be changed with the drop down menu below. Let the positive y-direction be up. The y-components of the electric field are shown in the drop down menu below.

N/C (Change electric field)

(Hint: Review Ch. 22 and 10 ) 
Question 1
Launch the electron for negative values of the field component. What is the sign of the  charge of the upper plate for these values. The lower plate? 
Question 2
Launch the electron for positive  values of the field component. What is the sign of the charge of the upper plate for these values. The lower plate?  
Question 3
When the field component = +12 N/C, what is the value of the y-component of velocity just before the  electron hits the detector ? What is your answer when  field component = +8 N/C? +4 N/C? (Hint: use the time of flight and Chapter 10 theory of projectile motion.) 
Question 4 (Extra Credit) 
Fill in the data table for a plot of the change in y vs  Ey. You must measure the change in y using click and drag.

Ey (N/C) change in y
-12  
-8  
-4  
4  
8  
12  

Question 5
Plot the above data in Excel. From the slope of the line through the data points, find the charge to mass ratio e/m. Compare with the theoretical  ratio by finding  the percent error.