Avery long uniform line of charge has charge per unit length 4.80 μc/m and lies along the x-axis. a second long uniform line of charge has charge per unit length -2.40 μc/m and is parallel to the x-axis at y = 0.400 m. what is the net electric field (magnitude and direction) at the following points on the y-axis: (a) y = 0.200 m and (b) y = 0.600 m?

a) 647 kN/C

b) -71.9 kN/C

Explanation:

Using Gauss law relating electric flux to the charge contained inside a surface we arrive at this equation for the electric field around a infinite charged line:

E = ρ / (2 * π * r * e0)

The electric field on the XY plane will be the sum of the electric fields caused by both lines:

E(y) = ρ1 / (2 * π * (y - Y1) * e0) + ρ2 / (2 * π * (y - Y2) * e0)

With

Y1 = 0 (the position in Y where the first line is)

Y2 = 0.4

e0 = 8.85*10^-12

ρ1 and ρ2 are the charges per unit of length of the lines

At point y = 0.2

E(0.2) = 4.8*10^-6 / (2 * π * (0.2) * 8.85*10^-12) -2.4*10^-6 / (2 * π * (0.2 - 0.4) * e8.85*10^-12) = 647 kN/C

At point y = 0.6

E(0.6) = 4.8*10^-6 / (2 * π * (0.6) * 8.85*10^-12) -2.4*10^-6 / (2 * π * (0.2 - 0.6) * e8.85*10^-12) = -71.9 kN/C

elly's long hair:

a. if the salon only takes cash, then this isn't the problem. it doesn't matter how much she has in her checking account.   she can't get a haircut until she has the cash.

b. if she has overdraft protection, then there's no problem.   she can go ahead and write a check that her account can't cover, then sometime later, pay the bank some outrageous usury for loaning her a few bucks for a few days, but with beautiful hair.

c. if elly has some principles, and doesn't want to write a bad check, then now she has a problem.   her desire for the new hairstyle is in conflict with her honesty and integrity.

d.   if the bank will not process a check she writes, then even if she had a million $$ in her account, she couldn't use any of it.   the amount she has in her account is not the problem.   and if i may suggest, she might as well close her checking account, and put the money where it'll work for her.   it's not doing her a bit of good in a checking account, since she can't write any checks.

justin can't pay the full balance:

a. he can't even handle the credit limit he has now.   under no circumstances should he ask for a higher limit.

b.   he can ask for the grace period to be extended.   but that's no solution, the bank will almost certainly refuse anyway, and there are much better options.   he knew the rules of his credit card when he started using it.

c.   he definitely should pay the interest on the balance, plus as much of the balance as he can cover at the same time.

d.   he definitely should pay the minimum otherwise they could shut down his card.   he should also pay as much more as he possibly can.   he should also remember the awkward situation he's in, stop buying stuff on credit that he can't afford, and avoid adding any more debt.

i'd say that justin's best best option isn't on this list of choices.   what he has to do:   pay as much as he can at least the minimum payment plus as much more as he can and then avoid adding more debt.

the assestment will probley apele with cause and effect