A proton moves 0.10 m along the direction of an electric field of magnitude 3.0 V/m.What is the change in kinetic energy of the proton? (e = 1.60 × 10^-19C)

Question

Quizplus · Accepted Answer

The work done on a charged particle moving in an electric field is given by W=qEd, where q is the charge of the particle, E is the electric field strength, and d is the distance moved by the particle in the direction of the electric field. 
In this case, the proton has a charge of +1.60 × 10^-19 C and moves a distance of 0.10 m in a field of 3.0 V/m, so the work done on the proton is W = (1.60 × 10^-19 C)(3.0 V/m)(0.10 m) = 4.8 × 10^-20 J.
By the work-energy theorem, the change in kinetic energy of the proton is equal to the work done on it, so the change in kinetic energy is 4.8 × 10^-20 J. Therefore, the best choice is A.

A Proton Moves 0