Giancoli Ch. 20 – p. 578-580, Problems #26-32, 36-39, 41-42, 47 key

26) 2.2 x 10^-4 T; about 4 times that of Earth

27) 69 A

29) 13 A toward top of page

30) 7.3 x 10^-2 N, attractive force

31) 2.5 A max

32) 2.2 x 10^-6 T; about 4% that of Earth

36) 2.4 x 10^-17 T

37a) (2 x 10^-5 T/A)(I – 15 A)

37b) (2 x 10^-5 T/A)(I + 15 A)

38) 1.4 x 10^-6 T; about 3% that of Earth

39) 4.5 x 10^-2 N/m attractive & 2.2 x 10^-2 N/m repulsive

41) 2.6 x 10^-6 N towards wire (attractive)

42a) 6700 A to the right

42b) not in stable equilibrium (it’s falling)

42c) 6700 A to the left, now stable