"At the bottom, the car has X joules of mechanical energy" is the one among the following choices given in the question that <span>the law of conservation of energy predict about the car. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer helped you.</span>
Answer:
C. 
Explanation:
The acceleration of an object can be found using the equation:

where
v is the final velocity
u is the initial velocity
t is the time it takes for the velocity to change from u to v
In this problem:
u = 30 m/s is the initial velocity of Angelica
v = 84 m/s is the final velocity
t is the time
Substituting into the equation, we find the acceleration:

Answer:
C) Use two batteries instead of one.
Explanation:
-Strength of an electromagnet depends on the electrical current which flows through the wires.
-Two batteries have a higher current than one and thus higher strength in the electromagnet.