A proton is projected in the positive x direction into a region of uniform electric field = (-6.80 105) N/C at t = 0. The proton travels 6.70 cm as…

A proton is projected in the positive x direction into a region of uniform electric field = (-6.80 105) N/C at t = 0. The proton travels 6.70 cm as it comes to rest.(a) Determine the acceleration of the proton.