To get a uniform field in the central region between the coils, current flows in the same direction in each.
Answer: 10.3m/s
Explanation:
In theory and for a constant velocity the physics expression states that:
Eq(1): distance = velocity times time <=> d = v*t for v=constant.
If we solve Eq (1) for the velocity (v) we obtain:
Eq(2): velocity = distance divided by time <=> v = d/t
Substituting the known values for t=15s and d=155m we get:
v = 155 / 15 <=> v = 10.3
The ratio of the turns to the voltage should be equal
i.e: 200/120 = t/12
so the secondary coil should have 20 turns
Answer:
Net pull = 110 N to the left
Explanation:
Group the different pulls according to the direction (right or left)
2 pull 196 N each to the right
4 pull 98 N each to the left
5 pull 62 N each to the left
3 pull 150 N each to the right
1 pull 250 N to the left
Since positive direction is to the right, the pulls to the left will have a minus (-)

The resulting force is negative, meaning the direction is to the left