Question

a proton is accelerated toward west at velocity of 10.5 m/s in 5s by an electric field. determine electric field strength
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Answer 1

a = F/m = eE/m

 

You did not state the units of the electric field.  I will assume it is given in newtons/coulomb.

 

e = 1.6 x 10-19 C

 

E = 4.0 x 104 N/C

 

m = 1.67 x 10-27 kg

 

a = (1.6 x 10-19)(4.0 x 104) / (1.67 x 10-27) m/s2 ≅ 3.83 x 1012 m/