Answer:
18.6012339739 A
Explanation:
= Vacuum permeability = 
L = Length of wire = 55 cm
N = Number of turns = 4000
I = Current
Magnetic field is given by

The current necessary to produce this field is 18.6012339739 A
I think is ocean but I'm not sure
Explanation:
Given:
v₀ = 250 mph
v = 0 mph
t = 25 s
Find: a
v = at + v₀
(0 mph) = a (25 s) + (250 mph)
a = -10 mph/s
A. it can be modified or rejected