Difficult expert magnetism problem

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Electrons in a television set are accelerated through a potential difference to reach a speed of 6.0 x 10^7 m/s before entering deflecting plates. To achieve this speed, the required potential difference can be calculated using the conservation of energy principle, where the potential energy is converted to kinetic energy. When a 200.0 V potential difference is applied across the plates, the electrons are deflected upward, necessitating that the upper plate be at a higher potential. The time taken for electrons to traverse the plates and their vertical displacement can be determined through kinematic equations, while gravity can be ignored due to its negligible effect compared to the electric forces involved. The path of the electrons will be a parabolic trajectory until they strike the screen, influenced primarily by the electric field between the plates.
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1.In a television set, electrons are accelerated from rest through a potential difference in an electron gun. They then pass through deflecting plates before striking the screen. (a) Determine the potential difference through which the electrons must be accelerated in the electron gun in order to have a speed of 6.0 x 107 m/s when they enter the deflecting plates.

The pair of horizontal plates shown to the right is used to deflect electrons up or down in the television set by placing a potential difference across them. The plates have a length of 0.0400 m and a separation of 0.012 m, and the right edge of the plates is 0.500 m from the screen. A potential difference of 200.0 V is applied across the plates, and the electrons are deflected toward the top of the screen. Assume the electrons enter the plates with a speed of 6.0 x 107 m/s and the fringing at the edges of the plates and gravity are negligible.
(b) Which plate in the pair must be at the higher potential (more positive) for the electrons to be deflected upward? Justify your answer.
(c) Considering only an electron’s motion as it moves through the space between the plates, answer the following:
i. The time for the electron to move through the plates.
ii. The vertical displacement of the electron while it is between the plates.
iii. Why it is reasonable to ignore gravity.
iv. Describe the path of the electrons from when they leave the plate until they hit the screen. State a reason for your answer.

The diagram is found here: http://es.tinypic.com/r/2ihmfcn/5

Any help is appreciated.
 
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Power of One said:
1.In a television set, electrons are accelerated from rest through a potential difference in an electron gun. They then pass through deflecting plates before striking the screen. (a) Determine the potential difference through which the electrons must be accelerated in the electron gun in order to have a speed of 6.0 x 107 m/s when they enter the deflecting plates.

For this part, consider conservation of energy, the energy the potential difference supplies is converted to kinetic energy.
 
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