The force the box is exerting on Manuel is the weight of the box, downward:

and this force is perfectly balanced by the constraint reaction applied by Manuel's hand, pushing upward.
X-ray)
because Electromagnetic waves are in act
Answer:
Incomplete question, check attachment for the graph needed to solve problem.
A 8.1nm........
Explanation:
Electric Field is given as
E=V/d
Where V is voltage
And d is the distance apart
E is the electric field
The voltage V just before action of potential is -70mV,
The value d=8.1nm
d=8.1×10^-9m
E=V/d
E=-70×10^-3/8.1×10^-9
E=-8.6×10^6 N/C
Then the magnitude of the electric field is 8.6×10^6N/C