303L-HW9

303L-HW9 - fierro (jmf2547) – HW 09 – berk – (60290)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: fierro (jmf2547) – HW 09 – berk – (60290) 1 This print-out should have 10 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 2) 10.0 points A positron is accelerated from rest between two points due to a fixed electrostatic po- tential difference, and acquires a speed of 28 % percent of the speed of light, which is 3 × 10 8 m / s. Denote m 1 as the mass of a positron, e the charge of a positron, and v 1 the velocity of the positron. Find the magnitude of the potential differ- ence | Δ V | between the two points. 1. | Δ V | = m 1 v 2 1 e 2. | Δ V | = 1 2 m 1 v 2 1 e correct 3. | Δ V | = em 2 v 2 1 4. | Δ V | = 1 2 m 1 v 2 1 5. | Δ V | = m 2 v 2 1 e 6. | Δ V | = 1 2 m 2 v 2 1 e 7. | Δ V | = 1 2 em 1 v 2 1 8. | Δ V | = 1 2 m 2 v 2 1 9. | Δ V | = 1 2 em 2 v 2 1 10. | Δ V | = em 1 v 2 1 Explanation: According to energy conservation, the po- tential energy lost Δ U by the positron be- tween two points is equal to the kinetic energy Δ K gained by the positron, Δ U =- Δ K Since the positron starts from rest, Δ K = 1 2 m 1 v 2 1 , Δ U = e Δ V Therefore e Δ V =- 1 2 m 1 v 2 1 , where Δ V is the potential difference between two points. Thus the potential difference is | Δ V | = 1 2 m 1 v 2 1 e 002 (part 2 of 2) 10.0 points A proton is also accelerated from rest between the same two points. Use 9 . 11 × 10 − 31 kg for the mass of the positron, with the mass of the proton given as 1 . 67 × 10 − 27 kg. What final speed will be reached by this proton? Correct answer: 1 . 96192 × 10 6 m / s. Explanation: Let : p = 0 . 28 , c = 3 × 10 8 m / s , m 1 = 9 . 11 × 10 − 31 kg , and m 2 = 1 . 67 × 10 − 27 kg ....
View Full Document

This document was uploaded on 10/10/2008.

Page1 / 6

303L-HW9 - fierro (jmf2547) – HW 09 – berk – (60290)...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online