Problem 11-55 Potential and kinematics in thundercloud - Part 6 - A

Under a particular thundercloud, there is a uniform electric field of \(9.3 \times10^3\; V/m\) upward.

An electron in the field, initially at rest, travels freely for \(3.5 \times 10^{-6} \; m\) before undergoing a collision with a gas molecule. Just before it hits the molecule, what is its speed? Use energy methods.

[Ans. \(1.1 \times 10^5\; m/s\)]


Diagram A showing the field direction and the direction of motion of the electron

\(E_{K1} + U_1 = E_{K2} + U_2\)


No. That is the potential energy for the special case of two point charges \(q_1\) and \(q_2\) separated by a distance \(r.\) Here we have a single charge in an electric field moving a distance \(y\).

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