This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: aldawsari (ma28683) HW05 Betancourt (16856) 1 This printout should have 6 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 23.223.5 001 10.0 points Two insulating spheres having radii 0 . 19 cm and 0 . 39 cm, masses 0 . 16 kg and 0 . 56 kg, and charges 4 C and 4 C are released from rest when their centers are separated by 1 . 6 m . How fast is the smaller sphere moving when they collide? Correct answer: 15 . 4996 m / s. Explanation: Let : k e = 8 . 99 10 9 N m 2 / C 2 , r 1 = 0 . 19 cm = 0 . 0019 m , r 2 = 0 . 39 cm = 0 . 0039 m , m 1 = 0 . 16 kg , m 2 = 0 . 56 kg , q 1 = 4 C = 4 10 6 C , q 2 = 4 C = 4 10 6 C , and d = 1 . 6 m . By conservation of momentum 0 = m 1 v 1 m 2 v 2 v 2 = m 1 v 1 m 2 By conservation of energy ( K + U ) i = ( K + U ) f 0 + k e q 1 q 2 d = 1 2 m 1 v 2 1 + 1 2 m 2 v 2 2 + k e q 1 q 2 r 1 + r 2 k e q 1 q 2 d = 1 2 m 1 v 2 1 + 1 2 m 2 parenleftbigg m 1 v 1 m 2 parenrightbigg 2 + k e q 1 q 2 r 1 + r 2 k e q 1 q 2 parenleftbigg 1 r 1 + r 2 1 d parenrightbigg = m 1 v 2 1 2 m 2 ( m 1 + m 2 ) . So v 2 1 = 2 m 2 k e q 1 q 2 m 1 ( m 1 + m 2 ) parenleftbigg 1 r 1 + r 2 1 d parenrightbigg = 2 (0 . 56 kg) ( 8 . 99 10 9 N m 2 / C 2 ) (0 . 16 kg) (0 . 16 kg + 0 . 56 kg) ( 4 10 6 C) (4 10 6 C) parenleftbigg 1 . 0019 m + 0 . 0039 m 1 1 . 6 m parenrightbigg = 240 . 237 m 2 / s 2 . and v 1 = radicalBig 240 . 237 m 2 / s 2 = 15 . 4996 m / s . 002 10.0 points A charged particle is connected to a string that is is tied to the pivot point P . The particle, string, and pivot point all lie on a horizontal table (consequently the figure...
View
Full
Document
This note was uploaded on 01/27/2011 for the course PHYS 251 taught by Professor Gavrine during the Spring '10 term at Purdue UniversityWest Lafayette.
 Spring '10
 Gavrine

Click to edit the document details