A proton has an initial velocity of 450000 m/s in the horizontal direction.  It enters a uniform electric field of 9600 N/C directed vertically up.  
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  <li> Why can you ignore the force of gravity in this problem?
  <li>Find the time it takes to travel 5.0 cm horizontally. 
  <li>The vertical displacement of the proton after it has travelled 5.0 cm horizontally.
  <li>The horizontal and vertical components of velocity after it has travelled 5.0 cm horizontally.
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