home > q&a board > physics > topic: electric field

Q BgQuestion:

Scholar
Karma Points: 200
Respect (97%):
posted by  chevy123 on 9/15/2008 10:01:54 AM  |  status: Live  

electric field

Course Textbook Chapter Problem
General Physics N/A N/A N/A
Question Details:
Two charges concentric spherical shells have radii 10 cm and 15 cm. The charge on the inner shell is 4.00x10-8C and that on the outer shell is 2.00x10-8C . Find the electric field at a. r =12.0cm and b. r =20.0cm.
 
Bonus Point Alert! Earn +4 additional karma points for helping this annual member.

AAnswers:

Answer Question
Oracle
Karma Points: 8,780
posted by booboo123 on 9/15/2008 10:21:32 AM  |  status: Live
Asker's Rating: Lifesaver   
chevy123's comment:
"thanks"
Response Details:


Using Gauss' Law:
E  =  k q / r2  ,  where q is the total charge enclosed


part a)
At a distance of 12.0 cm, both shells are "enclosed"  so the total charge is
4.00  +  2.00   =   6.00 x 10-8  coulomb
 
1/4pe 0 = 8.99 x 109 N-m2/C2
 so, E  =  8.99 x 109 * 6.0 x 10-8 / 0.122   =   37458 N/C

part b)
At a distance of 20.0 cm, both shells are "enclosed"  so the total charge is
4.00  +  2.00   =   6.00 x 10-8  coulomb
 
1/4pe 0 = 8.99 x 109 N-m2/C2
 so, E  =  8.99 x 109 * 6.0 x 10-8 / 0.202   =   13485 N/C
Answer Question
Ask New Question

Join Cramster's Community

Cramster.com brings together students, educators and subject enthusiasts in an online study community. With around-the-clock expert help and a community of over 100,000 knowledgeable members, you can find the help you need, whenever you need it. Join for free today » How Cramster is different than tutoring »

Need Help In

Useful Links