An elevator is moving down at a constant rate of 4 m/s. A person is standing on a scale that says the person weighs 80 N. When it reaches the bottom, it comes to a stop in 2 seconds.
During the stopping process, what is the reading on the scale?

The reading on the scale is 96.31 N.

Explanation:

When the elevator comes to a stop the speed decreases from 4 m/s to 0 m/s.

This means that it incurs deceleration. We can use the formula below to find out the force that is applied on the person during this deceleration:

F = mass * acceleration

Assuming the deceleration is constant, we have the following equation:

V = U + at

Where V = Final speed = 0

U = initial speed = 4

a = acceleration

t = time

Solving, we get:

0 = 4 + 2a

a = -2 m/s^2

Thus the object decelerates at 2 m/s^2

The mass of the person = 80 / 9.81 =  8.155 kg

F = 8.155 * 2

F = 16.31 N

Total weight = 80 + 16.31 = 96.31 N  (This is the reading on the scale)

a.   mass number from atomic number

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia