An electron, initially at rest is accelerated through a potential difference of 550 V. What is the speed of the electron due to this potential difference?

Question

Quizplus · Accepted Answer

We can use the equation for the kinetic energy gained by a single electron:

KE = qV = (1.602 x 10^-19 C)(550 V) = 8.81 x 10^-17 J

Since the electron starts at rest, all of this energy goes into its kinetic energy:

KE = 0.5mv^2

Solving for v gives:

v = sqrt((2KE)/m) = sqrt((2(8.81 x 10^-17 J))/(9.11 x 10^-31 kg)) = 1.39 x 10^6 m/s

Therefore, the answer is (E) 13.9 x 10^6 m/s.

An Electron, Initially at Rest Is Accelerated Through a Potential