Physics 121, Sections 9, 10, 11, and 12 Lecture 5 Today's Topics Homework 2: Due Friday Sept 16@6: 00PM Ch.3:#2,11,18,20,25,32,36,46,50,and56 Chapter 3: Forces and motion along a line Motion with constant acceleration Falling objects Apparent weight

Physics 121, Sections 9, 10, 11, and 12 Lecture 4 Announcements Lectures available on the web(short version) For over-enrollment please go to the Physics office P107 Laboratory sessions start next week Gotomywebsitewww.phys.uconn.edu/-rcote Syllabus+ homeworks lectures, etc Webassign gotowww.webassign.netandlogin

Announcements Lectures available on the web(short version) For over-enrollment please go to the Physics office P107 Laboratory sessions start next week Gotomywebsitewww.phys.uconn.edu/-rcote Syllabus+ homeworks lectures, etc Webassign

Lectures available on the web(short version) For over-enrollment please go to the Physics office P107 Laboratory sessions start next week go to my web site w. phys. uconn. edu/-rcote Syllabus+ homeworks lectures, etc WebAssign: ready Friday night gotowww.webassign.netandlogin )username: first letter of first name plus last name

Announcements Homeworks posted on WedAssign You need to register($10.00 by credit card) go to ww. webassign. net and log in >)username: first letter of first name plus last name

9-1如图9-1所示,一条无穷长载流20A的直导线在P点被折成120°的钝角,设d=2cm,求P点的磁感应强度。 解:P点在OA延长线上,所以OA上的电流在P的磁感应强度为零

8-1两个同心导体球壳A和B,A球壳带电+Q,现从远处移来一带+q的带电体(见图8-1),试问(请阐明 理由):(1)两球壳间的电场分布与无+q时相比有无变化?

1-1质点在xOy平面内的运动方程为x=3,y=27+3。求:(1)=2s时质点的位矢、速度和加速度:(2)从r=ls 到2s这段时间内,质点位移的大小和方向:(3)0~1s和1~2s两时间段,质点的平均速度;(4)写 出轨道方程

0-1已知a=127+4m,b=-10m,试分别用作图法和解析法求解:(1)a+b:(2)a-b。 解:(1)a+b=(127+47-101)m=(27+4万)

7-1把总电荷电量为Q的同一种电荷分成两部分,一部分均匀分布在地球上,另一部分均匀分布在月球上, 使它们之间的库仑力正好抵消万有引力,已知地球的质量M=5.98×02kg,月球的质量m=7.34×02kg (1)求Q的最小值;(2)如果电荷分配与质量成正比,求Q的值