Why Gravitational PE is Usually Negligible for Charges (4:44)
In this lesson, we compare electric potential energy and gravitational potential energy for a proton moving between parallel plates in a uniform electric field, and we plug in realistic values to show just how small the gravitational energy change is in this situation. You will learn how to calculate the change in electric potential energy using charge and potential difference, how to calculate the change in gravitational potential energy using mass, gravitational field strength, and vertical displacement, and how to use their ratio to justify when it is valid to ignore gravity in electric field problems. We also clear up a common confusion: even when gravitational potential energy is negligible, the mass of the particle still matters because mass controls inertia and therefore affects the particle’s acceleration and final speed.
Chapters:
0:00 Intro and the Big Question
0:52 Setup and Given Values
2:21 Calculations and Why Mass Still Matters
Chapters:
0:00 Intro and the Big Question
0:52 Setup and Given Values
2:21 Calculations and Why Mass Still Matters
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- Thank you to Christopher Becke and Julie Langenbrunner for being my Quality Control Team for this video.