3. A rocket is launched from the surface of a planet with unknown mass M , and radius r = 6.67 105 [m]. It is known that the planet is orbited by a small moon, which orbits the planet at a distance of R = 6.67 107 [m] from the center of the planet with an
38. We label these wires 1 through 5, left to right, and use Eq. 29-13. Then, (a) The magnetic force on wire 1 is
7 1 1 1 250i 2l 25 ( 410 T m A ) ( 3.00A ) (10.0m) + j= j F1 = + j= 2 d 2d 3d 4d 24d 24 ( 8.00 102 m )
0i 2 l 1
2
= (4.69 104 N) j. (b) Simi
1. (a) The field due to the wire, at a point 8.0 cm from the wire, must be 39 T and must be directed due south. Since B = 0i 2 r , i=
2 rB
0
=
2 0.080 m 39 10 6 T 4 10 T m A
7
b
gc
h = 16 A.
(b) The current must be from west to east to produce a field whi