Use the following figure to answer the next problem:
-A disk of radius 10 cm has a uniform charge density of 20 nC/cm².A small particle of mass m = 10 mg and charge q₀ = 5 nC is placed at x = 20 cm and released.The speed of the particle when it is a great distance from the disk is

Question

Use the following figure to answer the next problem:

-A disk of radius 10 cm has a uniform charge density of 20 nC/cm².A small particle of mass m = 10 mg and charge q₀ = 5 nC is placed at x = 20 cm and released.The speed of the particle when it is a great distance from the disk is

Quizplus · Accepted Answer

The correct answer is A because the electric field of a disk is the same as that of a point charge at the center of the disk. The force on the particle is therefore given by Coulomb's law, and the acceleration is given by F = ma. The speed of the particle when it is a great distance from the disk is then given by v = sqrt(2ax), where x is the distance from the disk.

Use the Following Figure to Answer the Next Problem