Answer:
2.75 N
Explanation:
Given that,
Box A has a mass 21.0 kg and box B has a mass 8.0 kg.
A horizontal force of 100N is exerted on box A.
Let a be the acceleration of the system. Using second law of motion,

Now applying Newton's second law to box B. So,

So, 2.75 N is the force that box A exerts on box B.
Answer:
Needs, Wants
Explanation:
Needs are necessary, wants are not
We know, Power = Voltage * Current
P = 660 * 12 = 7920 watt
In short, Your Answer would be Option A
Hope this helps!