A Charge Q = -610 NC Is Uniformly Distributed on a Ring

question 34

Multiple Choice

A charge Q = -610 nC is uniformly distributed on a ring of 2.4-m radius. A point charge q = +480 nC is fixed at the center of the ring, as shown in the figure. An electron is projected from infinity toward the ring along the axis of the ring. This electron comes to a momentary halt at a point on the axis that is 5.0 m from the center of the ring. What is the initial speed of the electron at infinity? (e = 1.60 × 10^-19 C, k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C², mel = 9.11 x 10^-31 kg)

• A) 6.6 × 10⁶ m/s
• B) 4.5 × 10⁶ m/s
• C) 3.4 × 10⁶ m/s
• D) 2.2 × 10⁶ m/s
• E) 1.1 × 10⁶ m/s

---

Definitions:

Perfectly Elastic

Perfectly elastic describes a situation where the quantity demanded or supplied changes infinitely in response to any change in price, represented by a horizontal demand or supply curve.

Industry Supply

The total output of a specific good or service produced by all firms in an industry at various price levels.

Industry Demand

The total demand for all the goods or services produced by a particular market sector.

Perfectly Elastic

Describes a situation where the quantity demanded or supplied responds infinitely or by unlimited quantity to any change in price, represented graphically as a horizontal line.