Answer:9.34 A/s
Explanation:
Given
radius of solenoid 
Emf induced 
no of turns per meter n=450
we know Induced EMF is given by

Magnetic Field is given by

thus 
Area of cross-section
where
solving integration we get

where r=distance from axis
R=radius of Solenoid



Answer:
Explanation:
Use the one-dimensional equation
which says that the final velocity of an object is equal to the object's initial velocity plus its acceleration times time. We are looking for time. That means the equation looks like this:
0 = 30 + (-4)t and
-30 = -4t so
t = 7.5 sec
I think this answer would be D. It was seen as a refueling station for naval vessels