Two long, parallel wires are separated by 2.2 m . Each wire has a 30-A current, but the currents are in opposite directions.

a) Determine the magnitude of the net magnetic field midway between the wires. Express your answer to two significant figures and include the appropriate units.
b) Determine the magnitude of the net magnetic field at a point 1.1 m to the side of one wire and 3.3 mfrom the other wire. The point is in the same plane as the wires. Express your answer to two significant figures and include the appropriate units.

a)10.9 mT

b)3.63 mT

Explanation:

Magnetic field B is equal Current* vacuum permeability /2* pi* R . r being how far the point is away from the current carrying wire.

We also have to consider the right hand loop rule to determine the direction of the magnetic field. Picture two wires with one having current upward and one having current downward being placed side by side. You put your thumb in the direction of the current and wrap your fingers around. the way your fingers curl is the magnetic field. the wire with current going down will have a magnetic field into the page on the left and out of the page on the right.  The wire with current going up will have the opposite. Therefore in between the two wires the magnetic field is going the same direction. and on the side away from the other wire they are going opposite directions.

a) The point midway between the wires 1.1m distance from both of them so this is the r value. since both wires have the same current and radius we just need to do the calculation once and multiply by 2 since magnetic field are in the same direction. we get the magnetic field of one to be 5.45mT therefore the total magnetic field at this point is 10.9mT

b) Since we know these two magnetic fields from the wire are in opposite directions we must subtract the two values. we know at 1.1 m away the magnetic field induced is 5.45mT now we plug in to find the magnetic field at 3.3 m away to be 1.82mT. Now we just subtract to get a magnitude of 3.63mT.

Hope this helps

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.

which three statements are true about all alloys?