an electron beam is accelerated horizontally from the rest by a potential difference of 450 V. if the beam then enters a perpendicular uniform electric field between two parallel plates, calculate the speed of electron as it enter the field

Question

welshfella · Answer

I don't think there's enough information given to solve this question

irishboy123 · Answer

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perl · Answer

I think the wording is a bit strange. 
This makes more sense, the beam enters a uniform electric field perpendicular to the plates.

perl · Answer

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perl · Answer

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irishboy123 · Answer

the second sentence is a red herring and this probably belongs in the physic section

the OP needs to calculate the energy of the electron as it enters the field -- he knows the energy it has acquired from the voltage, 450 J/C -- and convert that potential energy to kinetic energy.  the mass and charge of an electron will be in the OP's textbook and ubiquitous online.