The electric field at a point in space is E_vec = ( 200 hat{ i }+ 400 hat{ j } ) ;{rm N}/{rm C} .
What is the x-component of the electric force on a proton at this point?
What is the y-component of the electric force on a proton at this point?
What is the x-component of the electric force on an electron at this point?
What is the y-component of the electric force on a electron at this point?